99 rebuilt ISM misfire, black smoke, popping video inside

Just been rebuilt, all new injectors, new cylinder head. It’s misfiring, excessive black smoke and I can smell diesel from exhaust. It’s like an injector is stuck open. Unplugged each injector while running to isolate, no difference. Unable to run cylinder cut out on insight because fan clutch stays on so it can’t get to operation temp. No codes.

Replaced internal injector harness. Tested harness with test light and have strong signal to injectors

ohm new injectors all injectors reading .5 to 1.2 ohms. All new filters. Have 12 volts at fuel solonoid. Today I think I’ll check valve lash and report findings. I posted a YouTube video of what the engine is doing

https://youtube.com/shorts/qC3-whEXSDQ?si=mIJNGLjY7s_n8OYO

 

I went the route of an aftermarket rebuild on a 1995 12.7 L Detroit in 2009. First trip out it same symptoms: misfire, smoke, & smell of diesel. It turned out to be an injector tip cracked-or wasn't installed correctly when rebuilt. I gathered since that aftermarket sleeve kits are one thing, but always use OEM rebuilt injectors.

 

wouldn’t a cylinder cut out or unplugging that injector would isolate that bad injector?

 

Do a cylinder cutout the old fashioned way: drive it around enough to warm up. Then check the temperature of each exhaust port in the manifold with a laser temperature gun. Or really do it the old fashioned way and touch each port with a wet towel.

 

ok thank you very much. I will most definitely post the fix if I can fix it

 

Take it back to the shop that did the rebuild, or did you do it yourself?

 

myself.. but it ran for about 1000 miles and always felt like it was lugging..

 

Update

valve lash is set to spec and replaced cam sensor. Same issue. I hearing cam could be chewed up

 

Was it running like that before the overhaul? We rebuilt an ISM and it had low power and some smoke. It dropped 3 injectors in a week or so. If you have multiple injector problems would cutting out one tell the story? Maybe unplug one. If it does not make a difference leave it up plugged. Go on like that and find which ones are doing some work.

 

That is good advise but I have seen some electronic injectors put out enough fuel to generate heat. Maybe they spray out of time? Temperature was good but injector was bad. Yes this is odd. Cost me a lot of money.