Port Engine Smoke

[Artzco]

When I crank the port engine cold (8v92TA with 1100 hrs), I get a big cloud and then it goes away in about 5-10 seconds. It is definitely fuel smoke from the smell and I can see a small fuel film in the water for about 30 seconds. I talked to my diesel guy and he thinks it may be an injector(s) that may drip after the engine is shut down. My starboard engine cranks and runs clear.

I would like to get some opinions on this problem before diving into injectors. Thoughts?

Thanks.

 

[Genesis]

Probably a bad injector. Can also be some other much-less-fun things, like low compression in one hole that doesn't fire when cold (but does once it warms up a bit.)

I'm assuming reasonable conditions, a quick start once you hit the button, and good cranking speed since your other engine doesn't do the same thing.

 

[Artzco]

The engine starts right up each time and only has the cloud when cold. Even if I let is sit for a few hours, it will start up and not smoke. Also, it runs absolutely smooth and no evidence of running rough.

 

[J's Dream]

Art,

Sounds like an injector. Do you have a diesel guy up there? I replaced the injectors on my port 892 with Interstate McBee's. All 8 were good out of the box, and so far, so good with approx 100 hours (knock on wood).

Jason

 

[sportfish 45]

The normal aproach would be to isolate the cylinder by knocking out individual injectors one at a time. That's going to be hard to do if the smoke clears in 5-10 seconds. You could knock out one entire bank at a time to isolate which side. Then you'd half the cylinders to deal with. I would definetly isolate it and not just pull all the injectors. I'm not sure that the injectors dripping after shut down is logical especialy since it runs fine after start up. I'm sure one of the diesel experts on here would know if that can happen.

 

[Avenger]

Yeah, but which one?

An injector with a bad needle valve could get wet or develop a drip, post injection. Not being able to see it from here I would think there would be more symptoms, but if one was a good observer it's possible that could be it.

I'd also agree it would be preferable to try and isolate it. But if you can't do that and have to pull them all, make sure you tell your injection shop exactly what symptoms you're experiencing.

 

[Artzco]

Thanks to all for the input and the consensus seems to be injectors. My local guy said he can pull all 8 and take them to a shop and they will test and only rebuild any that need it. Sound reasonable?

 

[Genesis]

Yes.

If he has the proper equipment in the shop determining which one(s) are bad (bad pattern, leaking, etc) is pretty easy.

 

[sportfish 45]

NO

If it ran poorly that would make more sense but you say it runs fine except for the smoke on start up. Odds are good it's one cylinder. If that turns out to be true your removing and re installing 7 injectors for nothing. Isolate the cylinder. Check the compression on that cylinder if it's OK rebuild or replace one injector.