The Boating Forum - E-10 and vapor lock

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View Full Version : E-10 and vapor lock


ScarabChris
10-09-2008, 08:07 PM
Found an interesting article on vapro lock and ethanol. I am still having a random stalling problem at low speeds, and my nose cones and low water pick ups cause the engines to run a little hotter at idle.

ETHANOL PROBLEMS

By Robert Van Brunt
Chief Petty Officer U.S.G.G. ret

ETHANOL AND VAPOR LOCK

Short description:
When the engine compartment becomes hot either by climate or idling, and you use ethanol-blend gasoline it can cause excessive vapors in your fuel line and starve the engine of fuel. The engine can run poorly or stop and will not run until the fuel condenses.

THE PROBLEMS

Vapor Lock

Fuel containing 10% ethanol is called E10. If you have ethanol in your gas, you run the risk of creating vapor lock because of excess vapors.

Ethanol “boils” at 87ºF (at normal atmospheric pressure) and turns from a liquid to a gaseous state. By comparison, most automobiles have their fuel pump in the gas tank, so the whole system remains under pressure unlike boats whose fuel tanks are vented. In a closed system, the higher pressure raises the flash point of the ethanol reducing the amount of vapor that is produced. In addition, most automobile fuel lines are outside of the vehicle allowing them to stay cooler.

Since most boat fuel lines are in the enclosed space (sometimes even insulated) of the engine compartment, normal ventilation will not cool the fuel significantly enough to avoid the potential problems of vapor lock. Furthermore, since the fuel pump in a boat is mounted on the engine (versus a car where the pump resides in the tank) the action of the pump can reduce pressure in the tank to below atmospheric pressure and further reduce the flash point.

Boat engineers are aware of this problem and are reducing the likelihood of this occurring by reducing the suction required by the fuel pump, minimizing hose fittings and bends, and including a quality anti-siphon valve. In existing boats, fuel lines and filters should be kept as low in the boat as possible and tank vents should be cleaned and open.

Heat Soak

Most boats have “forced” ventilation. Air moves through the engine compartment when the boat moves forward. Heat soak happens after you have been at high RPM and then stop or drift on idle for a while. Because of heat soak the engine compartment will rise to a point where the ethanol will boil

THE CURE

To prevent vapor lock (i.e. boiling ethanol):

1. Make sure the engine compartment has adequate ventilation.
2. Relocate fuel lines to be low in the bilge. (The bilge is cooler because it is in direct contact with the water.)
3. Monitor the engine compartment temperature.
4. Add (or turn on) engine room blowers.
5. Keep the tank vent clean and unobstructed.

http://www.used-boats-canada.c...gines


chiselchst
10-09-2008, 10:47 PM
ScarabChris - 10/9/2008 8:07 PM
ETHANOL PROBLEMS

By Robert Van Brunt
Chief Petty Officer U.S.G.G. ret

ETHANOL AND VAPOR LOCK

Short description:
When the engine compartment becomes hot either by climate or idling, and you use ethanol-blend gasoline it can cause excessive vapors in your fuel line and starve the engine of fuel. The engine can run poorly or stop and will not run until the fuel condenses.

THE PROBLEMS

Vapor Lock

Fuel containing 10% ethanol is called E10. If you have ethanol in your gas, you run the risk of creating vapor lock because of excess vapors.

Ethanol “boils” at 87ºF (at normal atmospheric pressure) and turns from a liquid to a gaseous state.

This is nothing more than a case of incorrect information - no harm inttended I'm sure. But I see it all too often, time and time agin. I suppose it's proppagated by the confussion between deg F, and deg C. There is QUITE a difference between the two. Review the facts yourself. Review any Etahnol MSDS, and you'll soon see that ethanol does NOT start to boil (Intial Boiling Point) IBP untill much later, normally well over 170 deg F.

Referrence:
Boiling Point: 78 deg C which EQUALS 172.4 deg F
https://fscimage.fishersci.com/msds/89308.htm
http://www.csgnetwork.com/tempconvjava.html

78 Deg C = 172.4
Boiling Point: 173.3 deg F
https://fscimage.fishersci.com/msds/89308.htm
http://www.mathsisfun.com/temperature-conversion.html

Bottom line is, ethanol will not weather off as easily as the lighter ends in gasoline. It happens to be a very stable compound. However aromatic components will weather off first, which however, due the Federally regulated reformulated fuels, require even a LOWER aromataic content, making the newer reformulated fuels being able to store BETTER that previosly gasoline blends...not to mention the newer reformulated LOWER olefinic content - the component which more easily "turns to gums"...

So in a nutshell, regardless of what anyones says, the newer reformulated gasolines store as good or BETTER than the previous blends of gasoline.

"Federal and California reformulated gasolines will survive storage as well or better than conventional gasolines. The regulations require reformulated gasolines to have less light ends and less olefins (federal, later; California, now) thanconventional gasolines. As explained above, it is the oxidation of olefins that leads to gum formation. Reformulated gasolines also contain oxygenates. The common oxygenates are stable molecules that do not form gums.

http://www.chevron.com/products/ourfuels/prodserv/fuels/technical_safety_bulletins/ltg_storage.aspx

chiselchst
10-10-2008, 12:00 AM
However, some late model Volvo Penta's with EFI systems, can see a vapor lock condition, from a "too hot" engine compartment condition, resulting in a vopor lock situation. It is rare (but I have experienced it), and only occurs during "hot start" condition, only during a "hot start condition". When the EFI engines are restarted within maybe 15 of shutting down, while at normal operating temperature. The symptons are, much more starting revolutions required. Similar to a "flooded condition" with a carbureted engine. It is thought that the fuel vaporizes in the fuel runners, disrupting the designed injection quanity of fuel.

Mine personally, starts and runs fantastic cold, or if started after maybe 30-minutes of being *off*, after a hot shutdown.

This condition has been diagnosed by a few hot rodding, racing tech guys, which I cannot locate the post. But they were very respectable, and senior factory reps. Why VP hasn't addressed this, I have no clue...

This is NOT related to fuel or fuel volitillity, but rather a "too Hot" condition in the engine comartment of the engine, and the FI runners, etc. In fact, newly reformulated fuels are now "less volitale", due to new environmental standards...

Mercruiser had the same problem reportedly, but quickly made adjustments, reducing the T-Stat setings to ~165-170 deg F, thus having alleviated the problem.

Does anyone else have any info regarding this condition?


ScarabChris
10-10-2008, 04:58 AM
Well....I'm just searching for answers to my issue. And the description above describes it perfectly.

Only when I run E-10 do my engines stall out. And they only stall out at idle/low speed after idling for a good amount of time. And they will only start after a few mins and pumping the primer bulb feels like there is no fuel in the systam. All symptoms of vapor lock.

I would instantly blame the engine or fuel system but they run perfect on non ethanol blended gas.

debugger
10-10-2008, 06:23 AM
Chris,

If you want to test your vapor lock theory maybe try running around with the engine covers off.. or pull out the t-stats all together for a while.

Here's another crazy idea.. cool the fuel. Maybe get a couple extra feet of fuel line and coil it in a 5 gallon bucket of ice.

I know I'm going out on a limb here, but you seem convinced its a vapor lock problem. Personally, the way you describe the primer bulb as feeling empty until you pump it a while... I want to say you have an air leak in the lines. That combined with e-10, are causing your problems. JMO.

ScarabChris
10-10-2008, 08:22 AM
Well....just so I can say it was done I am putting all new fuel lines, clamps and primer bulbs in today....even though it runs perfect on non ethanol gas.

Some of the fuel lines and primer bulbs are original to the boat (1994). Also....I have the fuel flow paddle wheels in the fuel lines, they don't even work anymore so I'm taking them out. Who knows if they are clogged up. Doing that will also eliminate a pretty big loop in the fuel line.

If the problem persists after this I'm at a loss. What else can I do? I'll just have to take the boat in and demand that it be taken care of, its under warranty. For some reason they are stalling out only on E-10....the techs will have to figure out why.

This has become standard in my boating day, I have learned to deal with it. I already have the tecnique down to get them restarted pretty quick. And its doesn't happen all the time, a couple times a day maybe....but its getting old.

eggsuckindog
10-10-2008, 02:10 PM
Chris, honest I just don't think thats it, now I don't know exactly what it is but vapor lock probably isn't it. That article is referring to I/O's and inboards with enclosed engines, your fuel is only under the cowel a very short time and really has no place in the system to do it.

ScarabChris
10-10-2008, 03:11 PM
eggsuckindog - 10/10/2008 5:10 PM

Chris, honest I just don't think thats it, now I don't know exactly what it is but vapor lock probably isn't it. That article is referring to I/O's and inboards with enclosed engines, your fuel is only under the cowel a very short time and really has no place in the system to do it.

I know....I'm just covering all the bases. I'm at 5th base already.

So I did change all the fuel lines and primer bulbs. I split open a few sections of the old lines and they looked perfect inside. Oh well, now everything but the tank is brand new.

The one thing I found that didn't look good were the fuel flow sensors. These are the ones with the paddle wheels in them for the I-Command guages. Well after removing them I was blowing in them (hold the jokes please) and I found it very restrictive. Recently I have been having trouble getting the engines RPMs to max out, this could be the cause. Doesn't explain the stalling out only at idle and only with E-10 though.

Once I got all the new lines and primer bulbs in I pumped them up and started the engines. These engines never have a problem cold starting. But I ran them for a while at the dock and I noticed that the primer bulbs stayed very tight, the old ones never did that. They wouldn't flatten out but they would be soft and pumpable (hold the jokes again).

I will be putting a good amount of hours this weekend. If or when they stall again I'll make a note of the engine temps, RPMs ect.

If anyone has any ideas I'm all ears.

chiselchst
10-10-2008, 04:17 PM
debugger - 10/10/2008 6:23 AM

Chris,

If you want to test your vapor lock theory maybe try running around with the engine covers off.. or pull out the t-stats all together for a while.

Here's another crazy idea.. cool the fuel. Maybe get a couple extra feet of fuel line and coil it in a 5 gallon bucket of ice.

I know I'm going out on a limb here, but you seem convinced its a vapor lock problem. Personally, the way you describe the primer bulb as feeling empty until you pump it a while... I want to say you have an air leak in the lines. That combined with e-10, are causing your problems. JMO.
Good ideas. Cooling the fuel line might be the easiest, with more bang for the buck.

Also might consider using one of those IR temp guns, and checking the fuel system or fuel lines temps.

Weird problem. Please keep us updated, and good luck!

JackB
10-10-2008, 05:27 PM
For what it is worth, a good many years ago prior to E-10 we had a 32' Chris Craft on a trip when the engine bogged down in the middle of Lake Erie on the way to Canada. We limped into Canada and after a lot of checking found out that the small screens in the fuel flo sensors had gotten gunked up from all the sediment stirred up in the fuel tank by the rough conditions on the lake. We had recently installed the sensors and found out that thet fuel did not go through the fuel filters prior to reaching the sensors. We subsequently added filters in front of the sensors.

rwidman
10-11-2008, 03:07 PM
chiselchst - 10/10/2008 7:17 PM

......................... Cooling the fuel line might be the easiest, with more bang for the buck.

Back in the "good old days", many of my friends would clamp little flags of aluminum foil onto the metal fuel lines of their cars to cool the fuel and reduce vapor lock. ;)

MoJet
10-11-2008, 03:35 PM
FWIW - One place that I boat the air temp can be around 110+ F for days. In these conditions I would have really bad vapor lock issues. I had a 8.1L kodiak and kodiak in 07 began installing fuel coolers on the fuel system. They told me the boiling point of the new blended gas was around 136deg F (not c). The last time I was in this area and had the cooler, I did not have any issues with vapor lock with temps around 105 F. I've since repowered with a diesel but that is another story.

debugger
10-13-2008, 05:47 AM
Chris
Any update? How does she run now with new fuel lines?

ScarabChris
10-13-2008, 12:59 PM
Same shit. I put quite a bit of hours on the boat this weekend. I ran a total distance of 110 miles, some idle speed and some balls to the wall.

Again...any high speed running was fine, the engines produce plenty of power and it seems like they are even running a little better at the top end after taking out the clogged fuel flow sensors. But it is still stalling out at idle/slow speeds. It happened to both motors but not at the same time and only after idling for a little while. It happened about 4 times the entire weekend.

It doesn't seem like engine temp is a factor, it was happening at temps as low as 150 F, and thats head temp, I doubt there is that much heat in the fuel system but who knows.

One thing I did notice.....once when I felt the engine starting to stall I went back and pumped the primer bulb and it didn't stall.


I just wish I knew why it happens with only E-10. If it was doing it with non ethanol blended gas then I would no choice but to believe that both engines have the exact same mechanical problem and they both occured at the exact same time.

justfishin
10-13-2008, 02:14 PM
You have already changed all the fuel lines back to the tank.

What about the fuel pick up tube in or on the tank. It could have a crack or a small hole somewhere above the level of the gasoline in the tank. It could be in the anti syphon valve or even in the elbow or fitting connection.

I know that this is a long shot, but you have tried nearly everything possible.

ScarabChris
10-13-2008, 03:21 PM
Both pickup tubes, elbow fittings or anti siphon valves?

I have done about all I can do, I am going to take it in and let the pros take care of it. Thats what the warranty is for.

Skip
10-13-2008, 03:47 PM
I had about the same problem you describe with my 2002 Evinrude 200hp DI motor. It only happened when the water temp and air temp were very warm, water above 80 degrees and air in the high 80s and 90s. I took out the anti-syphon valve and it helped alot. I spoke to a good Evinrude mechanic at the boat show in New York a few years ago and he said the problem was the water cooled vapor separator. There is supposed to be an improved replacement but it's expensive. My problem was just the restart after waterskiing or a long run. Removing the Anti-syphon valve worked well. I justified removing it because the fuel line never falls below the top of the tank, so creating a syphon is highly unlikely.

deeper
10-13-2008, 04:50 PM
Just a thought. Why dont you carry a 5 gal tank with you and the next time the problem happens draw fuel directly from the little tank on one motor and isolate the problem from the motor foward if it fixes it or you will know its the motor if the problem continues.

marsea
10-13-2008, 05:13 PM
Quote:
Here's another crazy idea.. cool the fuel. Maybe get a couple extra feet of fuel line and coil it in a 5 gallon bucket of ice.


Any hot rod heads remember those Moroso cool cans? I had one in my Z28 and it worked awsome. My vapor lock was eliminated on mt BB chevy. Can't see any reason it wouldn't work in a marine application. You just fill with some ice from your cooler and its good for the day.

http://www.moroso.com/catalog/categorydisplay.asp?catcode=32030

ScarabChris
10-13-2008, 06:37 PM
I thought about removing the anti syphon valves from the tank. Maybe the E-10 is slightly more dense than non ethanol blended gas and the old anti syphon valves are causing just enough restriction to starve the engine at low speed.

Its acting more like lack of fuel than vapor lock. When it was about to stall I pumped the primer bulb and it stayed running. Very strange, there has to be something just a little different between the two fuels that the engine or fuel system just doesn't like.

I'll keep eliminating the little things until it either stops or I run out of things to try and have to take it in for service. I'm going to try removing the 14 year old anti syphon valves next.

chiselchst
10-13-2008, 07:47 PM
ScarabChris - 10/13/2008 12:59 PM
One thing I did notice.....once when I felt the engine starting to stall I went back and pumped the primer bulb and it didn't stall.
HUGE point - suggests suction leak somewhere. But would it indicate a leak prior to bulb, or after bulb? I don't know..

When engines are shutdown after the hottest conditions, and allowed to sit for 5-minutes, if you prime the bulb, does they start normally? If vaporlocked, I don't think they would?

chiselchst
10-13-2008, 08:00 PM
ScarabChris - 10/10/2008 3:11 PM eggsuckindog - 10/10/2008 5:10 PM

But I ran them for a while at the dock and I noticed that the primer bulbs stayed very tight, the old ones never did that. They wouldn't flatten out but they would be soft and pumpable (hold the jokes again).


EDITED: My bad - I got that tistwed around...

If the new bulbs are firm, and don't flatten out or collaspe, that's a great sign - maybe a leak on the downstream side of the buld was fixed..

But if the bulbs are NOW firm, and you can squeeze them at the dock to prevent stalling, those two items are not aligned? Maybe I misunderstood...?

deeper
10-14-2008, 04:17 AM
If you run one of the motors on a 5 gal tank with its own line to the motor when it happens again you dont have to keep guessing and buying parts. Also,first open your fill cap, if your vent is obstructed it will run ok at first idle (no negative presure) and at speed (when the motor sucks fuel hard ) but when you slow down your fuel pump will be fighting the negative presure in the tank. good luck.

ScarabChris
10-14-2008, 05:49 AM
All good points.

After idling the primer bulbs were not firm anymore, they could easily be pumped up. The new bulbs stayed firm during my little test at the dock but that was hardly real world conditions.

The tank vent....that was one of the first things I checked, its clear.

My next thing to try is going to be a vacume test on the fuel pump before and after removing the anti syphon valves.

debugger
10-14-2008, 05:51 AM
Your getting closer to the solution and I think you have eliminated vapor lock as the problem. Its got to be an air leak in the system or the tank is not venting properly. I think a vent problem would show at high speed however... they wouldn't run long at WOT if the tank wasn't vented. Remove the old check valves as you stated would be good.

What kind of lift pumps do etecs use... vacuum/mechanical or electric?

ScarabChris
10-14-2008, 05:59 AM
I believe they are electric pumps made by Carter

debugger
10-14-2008, 06:17 AM
I would double check that they are working 100% of the time. Its got to be an air leak. A little stream of bubbles is being drawn into the system and accumulating somewhere..in your racor and the lines....until stall time.

ScarabChris
10-14-2008, 06:32 AM
I'm very open minded to all the sugguestions, it just bothers the hell out of me that it only happens with E-10. After the first time I had this problem when I went back to non ethanol gas and the problem went away I was sure it was from mixing the two fuels.

Now its clear that whatever problem the boat or engines have is only effected or emphesized by E-10.

Yup...the air leak or restriction in the boats fuel system makes sense, but why it only affects the engines on E-10 doesn't.

bustedflat
10-14-2008, 06:42 AM
Another comment from the F.W.I.W. department. A fellow Auto Tech friend of mine has a 73 Camaro Hot Rod. Before E-10 even came around he was having vapor lock trouble. This was a show car that was driven very rarely. He was overdosing on Sta-bil to prevent his gas from going bad. His problem did not occur until he added the sta-bil and went away after he went back to straight gas.
My 96 Evinrude 225 will idle all day without stalling, but if I shut it down for short period and restart hot if I don't let it run a little it may stall when put in gear. Come to think of it that started around the time we switched over to E-10.

debugger
10-14-2008, 06:43 AM
not sure. Unless E-10 is softening up some fuel line at a connection making the leak worse. Racor filters screwed on good and tight? I think it was always that way its just that the engines don't run as well on E-10. The straw that broke the camels back.

I think it may be time to try a temporary tank on one engine and see if the problems go away. If they do... back to the boats fuel system.. replace anything you haven't already.

ScarabChris
10-14-2008, 07:29 AM
Ha...everything is replaced but the tank and anti syphon valves on the tank. Those are next.

jdupree
10-14-2008, 02:22 PM
I think that I have the same problem as ScarabChris. I have a brand new aluminum tank not even 1 year old. I noticed the other day that my Racor has little black particles showing up in the visible drain. I have a 200HP carb Mercury. Same problem, idle has not been good and will knock off after a minute or to. Do the little black particles sound like an e-10 issue?

ScarabChris
10-14-2008, 02:26 PM
Could be. But you do have fuel filters so the large chunks should be filtered out. Carbed engines will be easier to diagnose. If you are good with working on things you can take the carbs off and give them a good cleaning. Specifically the low speed jets.

Whaler27
10-14-2008, 02:51 PM
Another thought. Have you run over any shallow spots where you've ingested some sand or silt? If so, you might have a little restriction in the cooling water flow through the vapor seperator? Might pull the water lines off the separator and see if you can blow through it. If its anything like the Ficht version (I know its not eactly the same) there should be very little resistance to air flow. The cooling passages in the Ficht version clog up pretty easily. Maybe you've got some junk in there but not enough to set off any EMM overheat alarms. Might be enough of a restriction at low speed with low water pressure such that flow is not good but once you build up water pressure everything is OK. Worth a try.

c_mccann
10-14-2008, 04:12 PM
The Evinrude tech could see the pressure the lift pumps are making, could it be that the E-10 is wearing out the lift pump? Trust your gut, use your warranty...

ScarabChris
10-14-2008, 06:04 PM
Whaler27 - 10/14/2008 5:51 PM

Another thought. Have you run over any shallow spots where you've ingested some sand or silt? If so, you might have a little restriction in the cooling water flow through the vapor seperator? Might pull the water lines off the separator and see if you can blow through it. If its anything like the Ficht version (I know its not eactly the same) there should be very little resistance to air flow. The cooling passages in the Ficht version clog up pretty easily. Maybe you've got some junk in there but not enough to set off any EMM overheat alarms. Might be enough of a restriction at low speed with low water pressure such that flow is not good but once you build up water pressure everything is OK. Worth a try.



That is a very good scenario. I was thinking that exact same thing but just thought it would be so unlikely for both engines to get the same problem at the same time. I will check that out tomorrow.

As to warranty....word on the street is that warranty may not cover this so I need to try and rectify it myself. The lift pumps cost around 300 bucks plus whatever labor the dealer feels like charging. This could break a grand very quickly. If I can't figure it out I'll have to take it in and hope for the best.

Whaler27
10-15-2008, 04:52 AM
ScarabChris - 10/14/2008 9:04 PM

Whaler27 - 10/14/2008 5:51 PM

Another thought. Have you run over any shallow spots where you've ingested some sand or silt? If so, you might have a little restriction in the cooling water flow through the vapor seperator? Might pull the water lines off the separator and see if you can blow through it. If its anything like the Ficht version (I know its not eactly the same) there should be very little resistance to air flow. The cooling passages in the Ficht version clog up pretty easily. Maybe you've got some junk in there but not enough to set off any EMM overheat alarms. Might be enough of a restriction at low speed with low water pressure such that flow is not good but once you build up water pressure everything is OK. Worth a try.



That is a very good scenario. I was thinking that exact same thing but just thought it would be so unlikely for both engines to get the same problem at the same time. I will check that out tomorrow.

As to warranty....word on the street is that warranty may not cover this so I need to try and rectify it myself. The lift pumps cost around 300 bucks plus whatever labor the dealer feels like charging. This could break a grand very quickly. If I can't figure it out I'll have to take it in and hope for the best.

I've clogged up the separators on both of my Fichts at the same time running through a muck at low tide so it can happen to both. Also, in my case, I had little bits of clam shell fragments that would randomly block the outlet and cause the EMM hot alarm to go off while underway. It was totally unpredictable.

I'm not exactly sure how the vapor separator is constructed on the E-TEC but poke around the inlet and outlets of the vapor separator with a nylon zip tie and see if you see any residue on it.

ScarabChris
10-15-2008, 05:46 AM
I think its pretty much the same, its made by Carter and I know exactly where the water cooling lines go in and out. And I do occasionally suck up some trash as I have low water pick ups and the the water is very shallow at my dock at low tide.

I'll give the a shot, it seems very plausible.

Mr. Demeanor
10-15-2008, 06:18 AM
I am thinking anti siphon valves. They need a little suction to open and yours are getting sticky so they are needing more suction then your engine produces at idle. Thats how they stop flow in case of a broken fuel line. The siphoning effect of a leaking fuel line isnt enough to open the valve. Its also the easiest thing to check next. :)

theoldwizard
10-15-2008, 08:33 AM
Chris, sounds like you are facing the same "hot fuel handling" issue the car companies have been fighting for year !

All modern EFI/DFI outboards (that I am aware of) use a lift pump to bring fuel into a "secondary tank" (vapor separator) under the cowl. This is where the electric fuel pump picks up the fuel and send it to the injectors. The pressure regulator returns unused fuel to to the vapor separator tank. At low speed, a very high percentage of the fuel is doing nothing more than "running around in a circle" from the vapor separator tank through the fuel lines up to the regulator and back. This is the root cause of your problem ! The fuel is being heated as it passes by the rest of the engine and then it is returned to the vapor separator tank.

The vapor separator is simply "overwhelmed". On cars, the gas tank is vented to a charcoal canister that stores fumes. Via more lines and valves, these fumes are consumed by the engine. During long idles over hot roadways (think traffic jam in Houston during evening rush hour), so much vapor is created in the tank that the engine is running on almost 100% gasoline vapor, no liquid. Detroit's attempts to "minimize" the vapor is generically called "returnless fuel". That is, don't run the electric fuel pump at "full throttle". Somehow (and this differs from manufacturer to manufacturer) limit the amount of fuel sent from the tank to the engine to "just enough".

I'll bet if you could put a temperature probe inside the vapor separator it would be well over 130F. Changing things upstream (from the lift pump back to the main tank) will not solve your problem (as you have found out).

Solutions ? Somehow you have to do a better job of cooling that vapor separator. Another solution that the Coast Guard won't like, is returning fuel to the main tank. This a pressurized fuel line outside of the "engine compartment" (the cowl) which is a "no-no".

I have no facts to base this opinion on, but I would be curious to know that the temperature in the vapor separator tank is when you start to experience your problem.

ScarabChris
10-15-2008, 10:04 AM
Old Wizard....that is the most logical idea I have heard so far. It kinda goes with the idea that Whaler27 had about the clogged cooling line to the VSTs. It is also right along the lines of the other ideas about vapor lock. Makes sense, at high speeds the fuel isn't cycling around the engine long enough to heat up.

I just went out and bought a vacume guage to measure incoming fuel suction. I'm going to get those results today. I am also going to investigate the cooling lines to the VSTs.

I'll report back.

Demenor....there are no anti syphons, already checked that.

Whaler27
10-15-2008, 12:02 PM
ScarabChris - 10/15/2008 1:04 PM

Old Wizard....that is the most logical idea I have heard so far. It kinda goes with the idea that Whaler27 had about the clogged cooling line to the VSTs. It is also right along the lines of the other ideas about vapor lock. Makes sense, at high speeds the fuel isn't cycling around the engine long enough to heat up.

I just went out and bought a vacume guage to measure incoming fuel suction. I'm going to get those results today. I am also going to investigate the cooling lines to the VSTs.

I'll report back.

Demenor....there are no anti syphons, already checked that.

We use E-10 up here and we have lots of E-TECs of all sizes and I don't see /hear anyone complaining about this. So I don't think its a design issue of not having enough cooling capacity for E-10 fuel, but rather a potentially restricted cooling passage and as Wizard says, you get lots of hot fuel circulating around the system at low speed and if the VST cooling passages are somewhat restricted, you get problems. They need to put a flow sensor on the water going through that vapor separator.

Also, what kind of water pressure do you see with the low pickups?

ScarabChris
10-15-2008, 12:17 PM
Ok I did some testing, the results are interesting. I couldn't find a vacume test guage at the local Pep Boys so I got a boost guage. This guage shows vacume in one direction and pressure in the other.

The Stbd engine....this engine was the better of the two and on some days wouldn't stall at all, but it did on occasion.

I got a length of clear tubing and a T fitting and rigged the guage to the T and hooked the clear tubing between the boat fuel supply and engine fuel inlet.

No bubbles other than the one in the clear tube when I hooked everything up. The engine eventually pulled the air in the engine and there was no more air coming in. The vacume pressure holds at 2 PSI at idle or if I rev it. I'm told thats what I am looking for. No more than 4 vacume PSI is wanted or there is a restriction.

I couldn't get this engine to do anything abnormal.

The port engine.....this is the engine that stalls 95% of the time.

I gooked the test guage up in the same way. The air in the line doesn't want to get sucked in the engine and the needle on the test guage bounces from 1 vacume PSI to 4 PSI pressure. Only when I rev it up a little will it go to 1 vacume PSI but will soon go back to jumping around.

Also on this engine, while its idling I can hear the VST pump come on where I couldn't on the other engine. There is definalty something different with this engine. Sounds like a bad lift pump?

I left both engines running for about an hour, neither stalled but they usually don't in neutral, plus the engine cowlings were off so there was much less heat around the powerhead.

Also....I checked the cooling lines on both VSTs, both are clear and I even started the engine with the feed line off, they pump a lot of water.

My opinion? Bad lift pump on port engine. I don't know what the deal is with the stbd engine, perhaps they both have a problem with vapor lock in hot conditions but the port engine has the major problem.

Ideas?

Mr. Demeanor
10-15-2008, 12:35 PM
This still could be a bad siphon vlave on that engine. It drawas up to for 4psi then pops open and the pressure drops to 1psi which isnt enough to hold it open and it sticks again. Over and over....
Just an idea. Your moving in the right direction anyway. I would pull the siphon valve if its easy to access just for grins and redo your psi test.

Whaler27
10-15-2008, 02:50 PM
ScarabChris - 10/15/2008 3:17 PM


Also....I checked the cooling lines on both VSTs, both are clear and I even started the engine with the feed line off, they pump a lot of water.

My opinion? Bad lift pump on port engine. I don't know what the deal is with the stbd engine, perhaps they both have a problem with vapor lock in hot conditions but the port engine has the major problem.

Ideas?


Are you saying that you had good flow through the VST at idle? On the Ficht, the cooling water flows from the EMM to the top port of the VST through VST and then exits through bottom port of VST. Looks like it's the same flow path for the E-TEC but through a different VST.

ScarabChris
10-15-2008, 03:05 PM
Whaler27 - 10/15/2008 5:50 PM

ScarabChris - 10/15/2008 3:17 PM


Also....I checked the cooling lines on both VSTs, both are clear and I even started the engine with the feed line off, they pump a lot of water.

My opinion? Bad lift pump on port engine. I don't know what the deal is with the stbd engine, perhaps they both have a problem with vapor lock in hot conditions but the port engine has the major problem.

Ideas?


Are you saying that you had good flow through the VST at idle? On the Ficht, the cooling water flows from the EMM to the top port of the VST through VST and then exits through bottom port of VST. Looks like it's the same flow path for the E-TEC but through a different VST.

Thats exactly how its set up. I pulled the hose off the VST and I could very easily blow through it, no restriction. And at idle the water coming from the EMM flows very good. Plus after the engine has been idling for an hour the VST is almost cool to the touch, only slightly warm.

It looks like a lift pump on the port engine for sure, I'm going to change them both to be sure. I have been told that some gas stations in FL have been caught selling gas with as high as 40% ethanol. Which will do damage very quickly.

Amazing.......1000 hours without a hicup and along comes ethanol to screw that all up.

Whaler27
10-15-2008, 04:06 PM
OK, think we can rule out a VST low speed cooling passage restriction.

You might consider getting an ethanol test kit to test how much ethanol is in the fuel in your tank so you can determine what is going into the motors.

theoldwizard
10-15-2008, 04:11 PM
Whaler27 - 10/15/2008 12:02 PM
We use E-10 up here and we have lots of E-TECs of all sizes and I don't see /hear anyone complaining about this. So I don't think its a design issue of not having enough cooling capacity for E-10 fuel, but rather a potentially restricted cooling passage ...
You could be correct or it could be that the BRP engineers did not do extended idle testing in the tropics with E10.

Hot fuel handling is such an issue that Ford stopped selling Econoline vans with the "Ambulance Builder Package" with gas engine because the extended idles would cause so much pressure in the tank that it would force gasoline out the filler causing a potential fire hazard.

... if the VST cooling passages are somewhat restricted, you get problems....
Excuse my ignorance but what is a VST ? Vapor Separator Tank ?

They need to put a flow sensor on the water going through that vapor separator.
If the vapor separator is already water cooled, then I would then suspect a restricted water passage, like Whaler27 says.

I still say you need a temperature probe in the vapor separator to know for certain.

theoldwizard
10-15-2008, 04:18 PM
ScarabChris - 10/15/2008 12:17 PM

I hooked the test guage up in the same way. The air in the line doesn't want to get sucked in the engine and the needle on the test guage bounces from 1 vacume PSI to 4 PSI pressure. Only when I rev it up a little will it go to 1 vacume PSI but will soon go back to jumping around.
I'm guessing that is there something like a carburetor needle valve and float in the vapor separator to prevent the lift pump from "flooding"/overflowing the tank. The bouncing gauge sounds like it is not sealing properly.

theoldwizard
10-15-2008, 04:26 PM
Looking at the parts diagrams online, I see that there is a vent hose that goes through a restrictor to the throttle body. Check that the hose is not kinked anywhere between the vapor separator and the throttle body and you might even want to swap restrictors between engines.

ScarabChris
10-15-2008, 05:17 PM
Yeah I looked at all that, no kinked hoses. Not sure what the "restrictor" is but I am going to check with my dealer if the lift pumps will be covered under warranty. Either way I am changing them.

debugger
10-16-2008, 05:48 AM
You may want to redo your test with a gas can just to isolate the boats system and see if you get the same results before you buy lift pumps.

I just changed the lift pumps on my 200 yami as recommended by some after 5 seasons. Two pumps were about $40 each. Some engine models have 3 lift pumps and a high pressure pump. Yamaha VST's are not water cooled... at least mine isn't.

How many pumps do your engines have?

Whaler27
10-16-2008, 08:23 AM
Again, suggest that you test the fuel tank for how much ethanol is in it. If you got a batch with 40 percent ethanol, for example, you might have a problem with vapor locking even if everything is otherwise working perfectly because the system wasn't designed to handle fuel with more than 10 percent ethanol. Goes along with what the Wizard said earlier.

ScarabChris
10-16-2008, 10:09 AM
Ok.....did a couple more tests. One of which I could do before because I couldn't get the pressure guage hooked to the lift pump outputs.

Well I got a flexible valve stem extender for dually truck tires. It made it easier to hook the test guage to the lift pump out puts.

The stbd engine (this is the least problematic of the two) shot right to 4 PSI as it should.

The port engine barely gets to 1 PSI but probably closer to 1/2 or less PSI. However...reving the engine will get it to rise a bit. I guess thats why it runs good at high speeds.

Also.....I ran a long clear hose with the vacume guage in a T between the fuel water seperator and the engine. This way I could see if fuel was moving.

The stbd engine acted as expected, it was drawing 1-2 PSI vacume and I could see the fuel being pulled through.

The port engine was drawing almost no vacume but I could see the fuel moving but not the whole time. it would move a little then stop. But when I reved it the fuel would move faster.

My conclusion is this, I have a bad lift pump on the port engine which explains the stalling at low speeds. The stbd engine stalled a few times due to to much ethanol or heat vapor lock.

All that said, I have the cowlings off and both engines running at the dock for well over an hour now and they sound perfect. Why it wants to stall only while I'm idling in a busy channel is dumb luck I guess.

I found the gas to look a bit odd too. I took some out and put in a clear jar. Its very pee yellow, dark yellow. And you know how gas fumes look in the air? I can see that suspended in the gas. I have never seen that before.

Edit: After just 30 mins that jar of gas is now a dark cloudy orange and there is now water sitting on the bottom of the jar.

I must have way more than 10% ethanol in this boat, I guess I need an ethanol test kit. Where do I get that?

Whaler27
10-16-2008, 03:33 PM
ScarabChris - 10/16/2008 1:09 PM



I must have way more than 10% ethanol in this boat, I guess I need an ethanol test kit. Where do I get that?

http://www.aviationfuel.org/autogas/test_kit.asp

Until you know what you have in the tank, you could be :banghead:

bustedflat
10-16-2008, 03:44 PM
ScarabChris - 10/15/2008 6:05 PM

Whaler27 - 10/15/2008 5:50 PM

ScarabChris - 10/15/2008 3:17 PM


Also....I checked the cooling lines on both VSTs, both are clear and I even started the engine with the feed line off, they pump a lot of water.

My opinion? Bad lift pump on port engine. I don't know what the deal is with the stbd engine, perhaps they both have a problem with vapor lock in hot conditions but the port engine has the major problem.

Ideas?


Are you saying that you had good flow through the VST at idle? On the Ficht, the cooling water flows from the EMM to the top port of the VST through VST and then exits through bottom port of VST. Looks like it's the same flow path for the E-TEC but through a different VST.

Thats exactly how its set up. I pulled the hose off the VST and I could very easily blow through it, no restriction. And at idle the water coming from the EMM flows very good. Plus after the engine has been idling for an hour the VST is almost cool to the touch, only slightly warm.

It looks like a lift pump on the port engine for sure, I'm going to change them both to be sure. I have been told that some gas stations in FL have been caught selling gas with as high as 40% ethanol. Which will do damage very quickly.

Amazing.......1000 hours without a hicup and along comes ethanol to screw that all up.
Sounds like its time to invest in one of those Alcohol content test kits. I was refueling at a Shell station the other day and a technician from weights and measures was doing a routine check on their gas pumps. I don't know if it is just a Maryland thing or a federal requirement but gas stations here have their pumps checked regularly to make sure they are dispensing the correct amounts. I think they check the octane too, but not sure. I asked him if they do any testing for alcohol content. He said " not at all". This is where it gets interesting, he said "some of the oil companies were using the alcohol to tweek the octane one way or the other". ???? I don't think he actually knew anything about fuel, just how to perform his little tests and measurements.
Chris, I hope you get this figured out soon. Have you invested in an infrared temperature tester yet. I have the Raytek Minitemp with laser. I think I paid $50 for it. They come in handy for situations like this.

ScarabChris
10-19-2008, 06:54 AM
Update......I took the boat fishing yesterday. Lots of idleing and no stalling. The reason? Every so often I went back and pumped the primer bulbs tight.

Lift pumps for sure as far as I can see.

Why did they go bad? Possibly a high dose of ethanol that first time around. How knows but its been a long frustrating road. But now that I know the problem I'm happy.

debugger
10-19-2008, 07:16 AM
Congrats. :thumbsup:
One last suggestion from me... start filling up somewhere else. You win the award for the most times a boater can get a tankful of bad gas!

rwidman
10-19-2008, 07:19 AM
Just remember, every problem you have with your engine is not ethanol related. We had occasional engine problems before they started putting ethanol in gasoline. ;)

ScarabChris
10-19-2008, 05:15 PM
rwidman - 10/19/2008 10:19 AM

Just remember, every problem you have with your engine is not ethanol related. We had occasional engine problems before they started putting ethanol in gasoline. ;)

I agree...but for both to have issues exactly after my first batch of E-10 from a gas station that just started to sell it at the time would leave me to believe it was a bad batch of gas.

I got gas at a marina yesterday and it was non ethanol gas. That means I mixed it with the E-10 that was in there and the boat ran great. Though I did that knowing I would burn most of it that day and I did. I'll see next week, if it sits for a week and I am able ro run with no problems then in my case it wasn't the mixing that was the problem but the suddenly bad lift pumps.

Oh yeah...went out for an ICW cruise today and again no problems. I even towed one of my neighbors to his dock after he broke down. Funny....he said it was rinning fine a month ago and he put new gas in and it started acting up right away.

LouC
10-19-2008, 05:42 PM
We had some issues here when they went to E-10 gas about 4 years ago, I'm not sure if the problems I had were related to that or not, but I did have a corroded anti siphon valve and some water in the carb of my old 4.3 with the Quadrajet. After the mechanic did that work, back in 2004, I have not had further problems. I always check the gas in the water separating fuel filter for water but have not found any in the past 4 seasons. I am curious about the actual percentage of ethanol in the gas.

theoldwizard
10-20-2008, 02:04 AM
What everyone should know is that ethanol is an excellent fuel tank "cleaner". It will grab onto any "crud" in your tank, including water, and suck it out of the tank. If you are in an area of the country where you don't get a lot of E10, I recommend carrying a couple of spare fuel filters.

To be honest, I am shocked that there is anywhere in the US still selling gasoline that they claim has 0% ethanol. IIRC, the EPA ruled that no declaration of ethanol content was required if it was less than 10% (in other words, that are not required to tell you).

rwidman
10-20-2008, 06:21 AM
theoldwizard - 10/20/2008 5:04 AM

What everyone should know is that ethanol is an excellent fuel tank "cleaner". It will grab onto any "crud" in your tank, including water, and suck it out of the tank.

And it will also clean out the gas station's tanks. :roll

rwidman
10-20-2008, 06:24 AM
QUOTE]ScarabChris - 10/19/2008 8:15 PM

rwidman - 10/19/2008 10:19 AM

Just remember, every problem you have with your engine is not ethanol related. We had occasional engine problems before they started putting ethanol in gasoline. ;)

I agree...but for both to have issues exactly after my first batch of E-10 from a gas station that just started to sell it at the time would leave me to believe it was a bad batch of gas.

[/QUOTE]

That makes sense. There were some stories on local TV about people who bought bad gas and had their car's fuel systems and engines damaged. I've started keeping receipts for gas purchases just in case.

bquick
10-20-2008, 08:48 AM
When I change my 10 micron filters and dump them into a white bucket, I see alot od rust particles.
Now, tell me where the rust is coming from when I have an aluminum tank.

Yes, the marinas old storage tanks. They are above ground and get lots of condensation all winter long when there are no sales/deliveries.



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