Any Yamaha HPDI experts out there? still bogging down

[jdupree]

  Motor was "stumbling" at low rpms and did not idle very well.  Even if they are a little different, I would think they would display close to the same symptoms.

I have been wrong before, but I would bet heavy on the LP pumps.

John could you please define"stumble" ?

My OX66 150 starts after an few day sit with a 1-2-3 crank then idles fine.  On the idle off the dock there is a little smoke.. Then she runs fine at speed, when I slow down to idle sight seeing or trolling for any real length of time, she may sneeze (sounds just like a little old lady church sneeze) a bit of exhaust, and die but will start right back up, or sneeze and keep idling..  No real consistancy at this point.  WOT is 4900, but the wheel has a ding on one blade.  PO said the boat would do 43 at WOT, full fuel with 3 big guys.  With just me and a half tank I see 37 (which I was attributing to the ding)..

This sound like sick LP pumps?

Thanks!

Dave,

I just kind of threw "stumble" out there.  My motor would hardly idle and was hard to start.  It was running rough coming up on plane but then would smooth out.  Just do the quick test that I mentioned above on the LP pumps and we can go from there.

When was the last time you cleaned your 02 sensor?

[dburr]

Thanks John for the PM, and to answer the question, the motor is new to me so I have know idea what has been done other then clean oil in the lower unit and no overheating problems.. So I assume nothing. Time to make a list of things to verify/replace..

 

[BTF112989]

Well, here is an update. So I ran the boat from Saturday until Tuesday after my last post on here, and I thought my issue was all cleared up. After I changed the LP pumps, it bogged down a few times, but everything got better. The engine ran great the rest of Saturday until Tuesday. I took it for a little 45 minute cruise before I put it back on the trailer yesterday. During that cruise it bogged down 3 times. They weren't violent, but noticeable & enough to make me lose confidence in the engine again.

I did notice a few drops of gas leaking out of a fitting on the inlet into my high pressure pump. I need to check the o-ring in there when I go out next.

I guess if that doesn't work, I will try a remote gas tank.

-Ben

[BTF112989]

Hey everybody!
Just doing another update on this relentless issue & asking for any other suggestions as I've done a few more things.  

As you can read from previous posts on this thread, I have replaced all of the filters short of taking out all of the injector's filters & replacing them.  I fixed the leaky o-ring & buttoned everything back up in the high pressure fuel pump.  After running it some more, the same problem was still present.  So with most of my options worn out & me not wanting to just throw more parts($$$$$$) at the problem, I decided to bite the bullet/swallow my boat self-sufficiency pride & take it to the Yamaha dealer.  He lake tested it with the diagnostic computer hooked up & found that there were no fuel restrictions in the system when the bogging down or missing was occurring.  He did find that the sparkplug in cylinder #3 was not firing, which is the reason the boat couldn't get over 4600 rpms or so.  So he figured that was the missing problem, fixed it, and I picked up my boat.  I had replaced the sparkplugs pretty recently, so I didn't think they would be an issue.

I go to take the boat out on the lake yesterday, its running great at first.  Then, the problem comes back.  The first time it was three quick bursts of the engine missing/dropping around 300rpm before shooting back up to the normal rpm.  The misses only happen for about 0.1 seconds.  It missed about 5 times total over the course of an hour-long run.

The boat seems to run great when I start it & run it around the first time.  However, the problem always happens after the motor is shut off for 10 minutes or more, then started again to run across the lake again.  Never on the first start.  Maybe once things get warmed up, something starts working erratically.

Anyway, now I'm thinking its maybe one injector that works 99% of the time, but cuts out every once in a while.  Or maybe whatever the thing is that gives the injector its electrical charge cutting out every once in a while.  Does this sound reasonable?  Any other ideas?  I'm all ears.

I'm trying to pull the boat down to Naples, FL for Christmas & my dad's 60th birthday within the next 3 weeks & I'm trying to fix this problem fairly soon.


Thanks,
Ben

[dburr]

What a bummer Ben that you are still fighting with this!!!!

When the shop put the analyzer on was the engine warm and under load when the code came up? If had a code that showed a bad plug, the plug is swapped and the problem persists, maybe the wire to said plug is an issue?  I don't know if the analyzer is smart enough to pick up a broken wire or one with weak insulation that would break down when it got warm/hot and cause it to arc? You know which cylinder it is, maybe a carefull trace of the wires will show a burn to indicate an weak spot.  If you have access to a megohm meter (megger) that could help figure that out too.

Just a shot in the dark, good luck and you have my condolences!!

[gran398]

Agreed. Sounding like an electrical issue now.

[slvrlng]

Are you taking it back to the yammie guy? I would at least call him and tell him his "fix" didn't work!

[BTF112989]

Yes, the engine was warm when the mechanic realized #3 wasn't firing off. I looked over the insulation yesterday & didn't see any really obvious burned areas or weak insulation areas. I will have the yamaha mechanic check the wires out too.

Oh yeah, I'll be calling Monday morning to let them know the "fix" didn't fix it. They will usually give you a free hour of labor on the 2nd visit if the 1st visit doesn't fix it. I think I'll end up pulling it back in to them on Thursday morning.

I ran the boat for around 2 full hours yesterday without cutting the engine off. Went about 50 miles up river. I was trying to run it at various speeds to see any trends that may come up. In 2 hours of running usually 4400rpms or above, it hesitated 8 times. Only 2 being noticeable enough for a large rpm drop. The misses or hesitations don't seem as bad when you are at a higher rpm. The miss at 5000rpms was barely noticeable. The miss at 4200rpms was a lot more noticeable.


-Ben

[seabob4]

I'm thinking a weakened solder joint or defective component in the ECU, temperature related...intermittant open/closed circuit...

[BTF112989]

Thanks for all the suggestions guys!  Here's another update:
I took the boat back to the dealership & told them that it wasn't fixed.  I told the mechanic to look into it possibly being an electrical issue.  

So I leave it there, the next day I get a call back from the mechanic.  He says my new spark plugs with 2 hours of run time on them didn't look good again.  He found the O2 sensor to be so plugged up with carbon that it was not working.  He said it was the worst one he had ever seen in 15 years of working on Yamahas(I don't know why because I use startron & ring-free at every fill up).  He then guess that little chunks of carbon were breaking away in the cylinders after I ran it for a little while to get it warm, then hitting the spark plugs, thus causing the engine to miss.  He suggested doing a $500 treatment using YIEC (Yamaha Internal Engine Cleaner), which is apparently only available to dealers & some serious carbon killing stuff.  I okay'd that reluctantly.

He calls me back yesterday & tells me that he tested the boat out on the lake again.  As he came back to the ramp, it hesitated/missed again.  So he went back to the shop, got his computer & diagnostic cables.  Ran the boat again with the computer hooked up.  He got it to miss again 3 times.  Found no fuel restrictions.  Then low and behold he tells me IT MUST BE ELECTRICAL.  That's exactly what I told him after all of the suggestions yall gave.  He checked all plugs, wires, and coils.  They were all in good shape & operating correctly.  He checked the ECU & found one voltage output to one of the coils to be slightly low, but not out of range.  So he said he can't say that the ECU is bad because the low voltage isn't low enough.  The ECU is a $2000 part...

So I ask him what we should do next.  He says that he can't really do anything else because he can't find anything other things wrong with the engine to check.  He wants me to just run it until the coil goes out or the ECU goes completely bad.  He seems to think if I drive it until one of those parts goes bad, the hesitating/missing symptom will stop & my WOT will drop to about 4500 rpms.  Once that happens, he says we can replace the part that went bad.  So basically he is saying the part is sporatically going bad, but we don't know which one it is until it goes completely bad.

He said that I wouldn't run a cylinder lean because its still getting gas & oil.  He also said I wouldn't be dead in the water if either part went bad.  Just down one cylinder.  In retrospect, I should have asked him if he had an extra ECU or coil that he could install in my engine to see if one of those parts is the culprit.  I didn't though.

So my dad takes the boat out today to check it out.  It ran ok for about 45 minutes, then he took it back to the dock, let it sit for probably 25 minutes, took back off for another cruise, and on the way back to the dock it hesitated/missed 6 times(3 bad, 3 not so bad).

So SeaBob may be right with the ECU soldering guess.

Luckily the bill was only $230 this time instead of the $500-700 I was expecting.  So far I have a new set of sparkplugs & a carbon free engine for $430.  

Any thoughts, opinions, guesses, methods for getting this engine fixed or "accidentally" letting it jump off of my transom & to the bottom of the lake?

I'm guessing a broken solder joint in the ECU, a loose ground in the ECU, short in the wiring harness, other loose ground on the engine in a non-obvious place.  

Please help!  My Christmas trip to Florida with the boat in tow is slowly slipping away.

Thanks,
Ben

[gran398]

We sure feel your frustration.

The good news is for the most part she's running decent to good. She'll crank and run. Take her on vacation and enjoy her. If you get down there and find a cat-daddy Yammie guy...pay him a visit.

Every Johnson I've ever owned pretty much ran like that...but you'd get home.

Go ahead and pull it south

[seabob4]

Ben,
I have an '87 Maxima, love her, but she has trouble with alternators.  Or should I say, the re-manufactured Chinese junk they sell today has trouble.  Lifetime warranty, after the alternator was in, oh, say, 8-9 months or so, after about 15 minutes in the summertime, the voltmeter would drop to the negative side...totally heat related.  A diode issue for certain, but showed up normal when I would bring the thing back in for replacement.  I'd say, "Test it all you want, it's going to show up good...", just give me a new one.  

Temperature, components, solder joints, chips, resistors, diodes, caps...you just never know with electronic modules...

[BTF112989]

I would take it on down to Florida, but my dad said it was missing/dropping rpm's pretty badly today.  The boat almost fell off plane because the engine was missing so bad on occasion.  

SeaBob,
My suburban ate 6 alternators in 3 years, before I got the hint & put a brand new, non-remanufactured one in there.  12 years on the brand new one & its still running strong!  I hate electronic mechanisms and controls in engines for this reason.

The way I'm thinking now is an ECU is too expensive to take a shot in the dark at.  A new coil pack for my #5 cylinder including wire & spark plug boot is $93.  A fuel injector cleaning/filter change/spray pattern test is about $150.  And tightening up every battery connection & ground wire is free.

I'm thinking of tightening up all of the ground wires on the engine & really closely inspecting all wires on the main wiring harness for missing insulation, chafing, etc first.  If I don't have luck with that, then pull out my 6 fuel injectors & take them in for a cleaning.  They have been run for almost 400 hours with e10 gas that I tried to mitigate with startron.  Also, most people say that if you had fuel problems in the past(which I did), your injectors are most likely in need of a cleaning & basket filter change after that many hours.  If after an injector cleaning, the problem still persists, maybe check into that coil pack.  

And if the boat leaves me out on the lake all night because it will not run anymore, then I'll think about replacing that $2,000 ECU.  I'm that cheap!

Does this sound logical to all of yall?

I'm under the gun for time here to get this thing fixed for Florida.

-Ben

[BTF112989]

Update:
My dad tried to run the boat today. I had him run the engine straight off of the battery with no battery switch in between.

He checked all of the ground wires jethro1 mentioned in his above post. The grounds were all good & tight.

He went to start the engine(after running it on Thursday), it started well, then died when it was idling. He kept restarting the engine and it kept dying while idling. So, he started it & gave it some gas. It seemed to die even faster when he gave it gas than when he was idling. He finally got it to idle, but it was running rough & producing more smoke than usual.

After letting it idle for 10 minutes, it will start up & rev up great without dying.

He didn't want to take it out on the lake away from the dock, since no one would be around to tow him in this time of year.

So, dying after the initial start, or when you give it some gas, and producing more smoke than normal.

Would that be clogged injectors?

I was thinking electrical, but this has me thinking fuel again.

Thanks,
Ben

[gran398]

Ben, I'm with Lewis. Take it back to the Yamaha place and tell them its gotten worse.

Get them to go run it. Give them something to do, they're dead this time of year.

Keep us posted.