2001 chevy 2500hd diesel, when stopped and at idle truck emitting black smoke a little, when you step on it will get a little trail of black smoke for a very short period of time 206,000 miles, injectors were replaced @ 72,000, fuel injector pump and filter housing replaced 25-50,000 miles ago . I do have a code reader but as of today there has been no check engine light, so haven't used code reader. Haven't noticed a drastic drop in fuel mileage.

Solutions, MAF, erg.

looking for a little help

Thanks

Maybe an injector hung open?

No light almost always equals fuel system issue. Injector leaking just enough to smoke at idle

I was leaning in that direction before a little internet looking, what the best solution for finding which injector?

you can do a cylinder contribution test which almost never, in my opinion, tells you for sure what you need to know

Cost the same to test them as it does to replace them in reality, put a set in

Replace your air filter first. A dirty air filter will cause black smoke on a diesel engine. White smoke is fuel problem and black smoke is an air problem.

Listen to Hoggin, he’s a good mechic.

Yep

Black smoke is a your burning some fuel sign

Come look at my old 79 kw lay a duel black ribbon in the sky and watch the fuel hand drop and you’ll understand the connection. Kids call it rolling coal I think nowadays when you do it intentionally.

An injector dumping fuel will give the same results only it’ll gald a cylinder a lot quicker doing it at idle

Black..unburned fuel.

White is steam from burning coolant.

Id take Hoggins advise for sure.

White smoke is unburnt fuel not coolant.

Black smoke in bad air/fuel ratio. You are burning to much fuel because you can't get enough air/oxygen.

I'm just saying to check your filter first because it's the cheapest.