250 HPDI only at Idle issue

RocknReeln · 07-02-2009, 01:08 PM

2003 Yam. HPDI 250:

I have had this problem now for several months. It only happens at idle - so I have managed to use the boat frequently and it ALWAYS HAPPENS. When I start both engines or either they will go to 800 rpm and then they will not hold the crank (700,600, 500, dead) - they stall out every time, even after pumping the primer bulb. However, if I immediately put the engines in gear - they will run flawlessly (They pur).

Several months ago: I replaced the VST filters(diaphram), the separators, the clear bowls, the metal filter above the VST; changed the plugs - they were a little fouled but are and have been clean now - to no avail. I have also had my fuel tanks cleaned.

I NOTICED THE OTHER DAY WHILE ANCHORED IN A FAST MOVING CURRENT, THAT WHEN I CRANKED THEM THAT THEY HELD THECRANK !!!!AT IDLE----IT ACTUALLY HELD THE CRANK FOR THE ENTIRE TIME AND DID NOT STALL. It seemed that the fast moving water moving thru the lower unit and moving the props, kept the engines from stalling - so they held the crank at idle.

I recently thought it is a temperature thing, so I changed out my engine thermostats, but NO-GO. Here are the thoughts - some from mechanics, some from experienced boaters -- I am stumped. Please help. Thanks

Idle speed Control valve;
Throttle body;
Kill switch bad;
Boat hates me for not cleaning it often;

Curse of the anniversary missed while fishing;

bg2085 · 07-02-2009, 01:40 PM

do you think you might be getting air in the lines? i had a similar problem...turned out to be my racor gasket did not seal properly.

RocknReeln · 07-02-2009, 06:44 PM

I'll check - but doubt it because its both engines at idle and because there is no leakage and they run fine in gear.....as a side note -- I replaced both primer bulbs too.

There's nothing wrong with a free recommendation that seems logical....so fire away and THANKS! Yeah I'm a bit desperate

A1 Outboard · 07-06-2009, 04:09 AM

It sound like these engines need to be sync and linked using the latest service procedures. Your dealer should also watch the the engines operation using his diagnostic computer. These engine start on six cylinders and when warmed up drop to idling on four cylinders. Your problem is probably not a fuel problem because these engines have both an electric and belt driven fuel pump. This problem is hard to diagnose without the proper equipment. See your dealer.

RocknReeln · 07-17-2009, 08:34 AM

I have a neighbor that is a certified Yamaha mechanic. After your recommendation to hook up with the computer (dealer) and see if there are sync problems or any codes that are being flagged - We hooked up the laptop and both motors are running well - no codes thrown.

Neighbor's suggestion now is: to divert the fuel tanks, the fuel lines to the tanks and the separators and connect each engine to a separate 5 gallon gas tank to see if my problem is fuel related, hose related or possibly air or crack in fuel management sender or maybe something related to the tanks.

A1 Outboard · 07-17-2009, 08:59 AM

When the computer was hooked up did he check the operation of the shift cut switch? An improperly adjusted switch could cause a problem like yours. The sync link procedure has been changed from what it was when the manual for your engine was printed. Check the latest manual or the tech bulletin for the updated info. It is important to use a digital voltmeter to set the TPS voltage, the computer voltage tends to be low compared to the meter.

RocknReeln · 07-17-2009, 11:13 AM

Not sure of his checking the "shift cut switch"....he did crank it and put it in gear several times. Sure enough, it would immediately die at Idle---but when I shifted it in gear it ran smooth/well. So, while we tested them with the computer - this from my view I think was done to look for a history of codes thrown and none were. The laptop was connected only when the engines were off. That's when we then cranked it and at idle it died. We have checked the temperature sensors and electrical with a voltmeter and it read 13.5v....

RocknReeln · 07-17-2009, 11:51 AM

O'h ...something else to add. While troubleshooting this issue I noticed that my trim/tilt was not working - opened the fuse box and sure enough the fuse was blown. I replaced it and it blew again. We troubleshooted it all the way to the dual switch panel. Yep....you guessed it, had to replace the whole Dual key switch panel, alarm horns, brain, etc. The good news is my trim tilt works again (By the way its much cheaper to buy the whole Switch panel Kit MSRP $275 then individual pieces $450) The bad news is, it didn't fix the idle stall problem and I'm out $275 for an unrelated problem.

A1 Outboard · 07-18-2009, 06:17 AM

The most important voltage setting is the throttle position sensor (TPS). The voltage spec is .58-.62. Some techs have good luck setting the voltage to the top end of the spec. 13.7 volts is the output of the alternator. The engine sensors operate on a 5 volt source that comes from the engine computer. The engine diagnostic prgram is used both with engine off and running. You can watch the operation of the shift cut switch with the diagnostic program. Watching the engine stall with the computer attached should give a clue to the problem.

RocknReeln · 08-06-2009, 05:56 PM

OK...finally figured things out. First, thanks A1outboard!

Second, there's good news and bad news. GOOD NEWS: I have checked the TPS sensor and all settings are good. My mechanic pulled the belt off of the top of the port motor - guess what it ran great at idle! Then, same was done for the starboard side - it ran great at idle! Now for the BAD NEWS: looks like my High pressure pumps are dirty or bad. My mechanic/neighbor says that they don't clean them. But - I recall a company in Florida that you can ship them to for cleaning -- is that true? Because the ticket price will put me away for months!

Thanks to all that helped!

RocknReeln · 08-11-2009, 05:01 PM

Alright a bit of a status report for those interested. The company that does the High pressure pump cleaning is Flagship Marine out of Punta Gorda. I have not sent the pumps to them yet. I had the engines looked at by a Yamaha Master mechanic in Marco Island Florida and he replaced several of the spark plug caps that he said did not pass muster (using a Voltameter/Low Ohms) He set the Throttle Position to spec .58-.68 -- setting at the high end, the n he adjusted the pressure in the VST somehow. Either way - it now Idles well. I may still send the injectors to be cleaned at Flagship.

Bogii · 08-12-2009, 12:55 PM

Quote:

Originally Posted by RocknReeln

Alright a bit of a status report for those interested. The company that does the High pressure pump cleaning is Flagship Marine out of Punta Gorda. I have not sent the pumps to them yet. I had the engines looked at by a Yamaha Master mechanic in Marco Island Florida and he replaced several of the spark plug caps that he said did not pass muster (using a Voltameter/Low Ohms) He set the Throttle Position to spec .58-.68 -- setting at the high end, the n he adjusted the pressure in the VST somehow. Either way - it now Idles well. I may still send the injectors to be cleaned at Flagship.

glad you kept us updated
can you please tell us our ask how the vst pressure was ajusted??
never heard of that.

Thanks Bogii

RocknReeln · 08-12-2009, 04:26 PM

Apparantly there is a pressure valve at the top of the tank - I think he made an adjustment there. All I really know is that he asked me how the oil consumption was and at that time was making an adjustment above the tank. I may be wrong. But all I know is that now the engine idles well - no stalling at idle. It seems to have been either the caps at the plugs that were replaced (high OHMS/over 5.50) or the adjustment to the TPS (pretty sure it wasn't that, as it read properly before) or what he did at the VST tank.....I am a complete novice and will tell you that having a "master yamaha tech" for only two hours take a look at this issue --- made all the difference in resolving this problem. I guess I learned my lesson with my mechanic/neighbor and having other non-certified/non master tech's look at this.

DEVLDOG · 08-14-2009, 11:36 AM

Glad you got her runnng right again!

saywot · 10-02-2009, 05:57 AM

RocknReeln,
I have a 27 Sailfish GW w/ twin 04 300 HPDIs and have been contending with the exact same problem you have described. The concern started after the oil pump update about 1 yr ago and I've had it back to the local dealer since then with a "no problem found" diag. It sounds like I need to take the boat to another dealer. Can you share the place you got your engines fixed at? I'm also located in FL.
Thanks,
David

saywot · 10-14-2009, 10:54 AM

Has anyone in this forum figured out the root cause of this issue? I know I'm not alone on this and wonder if I'm just being to picky. Would it be to much to ask that 04 MY 300 HPDI engines start and stay running on the first attempt? Since my last posting I have checked the TPS voltage setting and throttle sync but have only managed to get them to stay running after the 2nd start attempt. I basised the settings to the upper speci. 0.62 volts at idle. Any info would help.

saywot · 10-15-2009, 05:45 PM

Bump, how about a survey on how many cold start attempts before either a 250 or 300 HPDI will stay running. Let's make that 03 MY and up.