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Random Quote: Somebody just back of you while you are fishing is as bad as someone looking over your shoulder while you write a letter to your girl. ~Ernest Hemingway
Hal, thaks for the simple but adequate description of the compressor failure....i don't think I have that as the engine sounds just find except when it is surging or about to stall but nothing really "bad".
I can't find a part number for the tracker valve / diaphram , maybe I am not looking in the right place.....is it on the fuel rail or in the VST? I see a diaphram on the fuel rail but it doesn't have a part number.
Looks like I can't get it on the DDT before saturday.
Thanks.
Ok, maybe I found it, looks like it is on the starboard rail? The part is called diaphram assembly for ONLY $104 !!!!! Wow, maybe I should have looked at the diagrams and prices for parts before I bought these engines!
$104.00 is list, check boats.net. Poke around on the parts lists while your there and check the prices on those fuel and air lines that feed the rails!
Haven't done stats. yet have ya! How about them $12.00/ea spark plugs!
Opti oil becomes the cheapest thing for these engines. Keep us posted on
how your making out with the problem.
There is a fuel regulator diaphram and and air regulator diaphram. Both are on the port side of the engine if you are facing forward on the inside of the fuel/air rail. The both look identical from the outside. The top one is fuel, the bottom is air. Mine would not run at all when the fuel regulator diaphram went bad.
So, I will open up the regulator and see if the diaphram is ripped...right? No reason not to from what I can tell.
Bruce, I will defiitely look for the part cheaper than list, just kills me that a diaphram can cost $104. I got the spark plugs from Advance Auto Parts for $9.99 (plus 10% military discount) so not too bad I guess.
I will do this tomorrow morning and report back, if this is it, i guess I will have saved the money from the diagnostic which will offset the cost of the part.
Timebandit, thanks for the insight. Will the DDT show a fault code for the tracker valve? Is the diaphram something I can change out myself or is it an assembly that I can buy/install? I will look at my diagrams again for this.
You are the first one to come up with a good explaination for the high rev on start up (other than the TPS which I swapped with no joy).
The fun continues!
Negative on the DDT. The tracker valve in purely mechanical. It is on the stbd. rail. (This engine has a special set of expensive dual manifold gauges used to check out the fuel and air pressure.) And it still may not show up that well. The valve is simple to replace if you have the right special tool to compress the stout spring. You can improvise by using threaded rods and nuts in the first two bolt holes.
Timebandit, I got to hand it to you, the tracker valve was the culprit! I swapped the one from the port engine (it really wasn't difficult at all) and violla it runs pretty darn well. I did still get a high rev on the initial start-up but it settled right down and idles smoothly. The bad (starboard) one had an 1.5" tear in one side and a small rip in the other. The "good" one had a .5" tear in one side and a very small tear in the other so I think I need two new ones.
The really badly torn one I super glued back together and I put it into the port engine that wasn't having a problem to begin with....it runs better than the starboard still. I guess a true test would have been to just install it the way it was and see if it made the port engine run as badly as the starboard was.
Anyway, I will be ordering two of these. Thanks to everyone who took the time to help troubleshoot and hopefully others will learn from my experience.
I just water tested the boat and while I think I fixed one problem.... I may have caused another? The troubled engine now idles beautifully, but we went out on a test run and it wasn't great. At first I only got about 4500 rpm on the stbd engine w/5200 on the port and that was after it sat at 4000 RPM then it kicked up to 4500? I throttled back and tried again....idles great but then would only get up to 4000 RPM.. Not sure what is going on now but I could only get 3000 RPM out of it for a little while then would kick up some but not much maybe to 3500. I pulled the cowl and checked all the plug and coil wires in case I left something off but everything was in order. Tried again and it was even worse.....still idles great though.
$104 is nothing. The port rail costs $800 if those regulators fail. You don't fix those on some engines.
Anyway, next problem.
It seems like the motor can't find fuel. The VST is staying full of gas? Check out all the Grey fuel lines. They get artery clog. Merc knows about the problem and has updated all the tubing and primer bulbs.
Fuggin' ethanol
I don't have any grey fuel lines....the boat is a 1976 and has been rerigged many times. Any fuel lines that I have replaced are all the alchohol resistant. I don't know if the VST is staying full but will check. This just started and is progressing all too quickly, maybe ethanol is the main player here don't know. It begs to quetion why the other engine is OK? I put everything back the way it was except for the tracker diaphram and the throttle position sensor which were swapped from the other engine, I double checked all the electrical and didn't touch anything else... Not sure what else to do, if the VST were to be emptying...I could hit the throttle right off the bat and see what happens, if it is the problem I would lose RPM as it empties.
Similar condition last week except for the idle up to 3000 and then back to 600 like you experienced.
While running at cruise ,one engine would surge up and down. Smartcraft said all temps and pressures ok while running but evidently I was one cyl short. Problem was found to be a bad air injector on one cylinder. Not a pretty fix, with the part around $360 and labor of 2 hrs. And just think with twins I've got a total of 12 air injectors and then fuel injectors as well!!!.
Servicer got me in the next morning after I called and I had the boat back in the afternoon.
Ouch! That air injector is available through Pro Marine for about $250 (I dont remember exactly but it was under $300) and itakes about 10 minutes to change one. I lost three when my compressor blew last time.
I did not read to the end but you can check your compressor by pulling the belt off both engines. Turn the compressor pullet back and forth by hand. If the engine that is acting uo sounds different when doin this, you probably have a bad compressor.
To pull the belt, use a ratchet in the square hole on the tensioner and loosen it.
A compressor runs about $750 and takes a few minutes to replace. You also need to replace the filters in the oil lines feeding and draining the compressor. You should also put the engine into breakin mode with a new compressor. That will feed oil to it initially and over oil it while it breaks in.
Edit, I see your on your way.
Tiem Bandit, I actually dissasembled and reassembled my port rail....successfully without the special tool. Not that I would do it again but my rails were full of metal from the compressor piston. I do not advise it. I think the spring in the port rail valve is a valve spring from a top fuel dragster.
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Out of town till Weds. when I will resume troubleshooting.
If I am looking at a fuel restriction of some sort, is there anyway to tell if the VST full or not? I was thinking if I just hammer down right off the bat I may get full throttle then as the VST drains I will be limited due to the fuel restriction.....does this make sense to try or is there another way to tell if the engine is fuel starved? It seemed to be getting worse each time I tried to get full throttle out of it which I guess would make sense if I have a restriction that is getting worse. I will have to check again all the fuel lines/primer ball but I am pretty sure I don't have any crappy grey lines.
Any other thoughts?
Timebandit was right again! It was a fuel issue. I had jut gotten the boat back from being painted and it seems that the guy doing the work cut the fuel line and ran it in a way that there was a very sharp 180 degree turn which I think was restricting flow at the higher RPMs. I put a longer section in w/out the sharp turn, removed the fuel flow sensor in case that was clogged and swapped primer balls from one engine to the other. Both engines ran great, I had 10 people on board and got 5200 RPM on each. I think I am back in business and it really didn't cost much at all.
Thanks again to everyone that took the time to help troubleshoot I really appreciate it.
What do I know around here, huh?
Why is there a flow sensor on an Opti? The S/C gauges get that info from the ECM's that know exactly how much fuel they are injecting.
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