6v92 fuel problems

[hwginc]

newly rebuilt completely including injectors but i am having a problem
idles, rives up , and it sounds great, slight puff of black smoke clears right up
however on the test run in gear from 500-800 rpms it does fine over that a lot of black smoke , put it back in neutral rive it up it cleans right up .
can ran it 2000 rpm in neutral and no smoke WHAT does you all think the problem is, thanks

 

[SKYCHENEY]

It must not be getting enough air. Turbo?

 

[CapetaniosG]

Have you checked the emergency stop to make sure it is fully open? Are the injectors timed properly? Are the injector rack control levers positioned properly? Have you measured the exhaust back pressure? Is it within specs? Have you checked your air intake for obstructions? Your Governor may need a tune-up after you time your injectors. Black smoke is normally associated with incomplete fuel combustion, excessive fuel or iregular fuel distribution.
Check the above and your problem may be solved.

CapetaniosG

 

[hwginc]

No ,rebuilt will suck you hand off ,has the whistle sound' that was my first thought if seized it would do the same thing

 

[hwginc]

had governor redone when blower rebuilt,rack is set right and timed no air restrictions that are apparent , but again runs and sounds great 500-2000 rpms until you try to put it under load

 

[Finalee]

Is the bottom clean?

 

[CapetaniosG]

The fuel consumption is a lot more when the engine is under load vs. when it is not. That means that the amount of air needed for proper and complete combustion (while the engine is under load) is not there,thus incomplete combustion and black smoke. That is, if all other things I mentioned in my first post have been checked and are ok.

capetaniosG

 

[Genesis]

Airflow.

If you're getting black smoke you're getting the fuel but not the air to burn it.

No load doesn't tell you anything - it takes almost nothing to spin these out of gear in terms of actual fuel burned.

 

[Brian Degulis]

If your certain you have no air restrictions and your certain that your bottom is and props are clean and that the tune up procedure was done correctly and the valve train timing is correct not off a tooth after rebuild. Then your left with just one thing one or more injectors that aren't poping off right when fuel delivery is high. That's rare but it does happen who supplied the rebuilt injectors?

Brian

 

[hwginc]

Guys, I'm going with the turbo idea will go down to the boat tomorrowand pull the air filter and see if the fins will free spin / stewart stevens rebuilt the injectors Thanks for your help so far will report thursday jack+

 

[REBrueckner]

All good suggestions.

Is it generally correct that IF the turbos are spinning at low RPM, say 500 to 800 RPM, and there IS black smoke, likely it's NOT a turbo problem??? (unless of course somebody left a rag in there somewhere which is blocking air flow)

 

[captddis]

check the blower bypass valve. I hope the aftercooler was cleaned when the blower off. Check carefully for air leaks.Double check the cylinder kit #s. If you have the engines I think you have[ the ones with the shell and tube exchanger and the low profile manifolds] they were twin turbo engines that Covington converted to single turbo forward plan bypass blower engines. Ordering parts by serial# may cause problems on those.
They are advanced timing engines and injector setting is 1.508 Dave

 

[hwginc]

Returned from boat the turbo's are spinning and sucking fine with several free wheeling spends at shutdown i'm am starting to believe it is the fuel rack
any advice on setting or someone to contact would be great again THANKS
jack