Truck is 2004.5 with 225k miles, no mods other than Smarty Jr on fuel saver setting.

About 15k ago truck began to have excessive black smoke under throttle over half way. Also noticed smell of fuel in oil. Due to mileage and still being on original injectors I replaced all of them with new Bosch injectors and tubes from injectors direct. After that I had oil changed.

After the swap mileage has gone from 20avg to 13 avg on overhead. I am aware it’s not likely accurate just using as a baseline. The truck now also has heavy white smoke for 10-20 seconds on startup regardless of temp. I keep it in a heated shop, but it is winter so I can see it when warm and cold out. I checked oil and it “appears” to smell of diesel and be thin. Not sure if this is residual fuel from oil change not being a 100% exchange?

other related info: truck starts right up no delay. Throttle response is immediate and strong. Still get lots of black smoke under throttle but less than before injector swap.

i’ve done a lot of searching and reading different threads. Seems like it is either a bad replacement injector, or a leak from the CP3 pump. I’m really hoping it’s the pump as I don’t want to do. The injector swap again. Is there anyway to test the CP3 in the truck? Can it be fixed if it is leaking into the crank case? Or due to the mileage on the pump should I just replace? Am I barking up the wrong tree?

 

It does sound like an injector.

But i would check the oil level to make sure it's not gaining, retorque the tubes and if thats all ok then have the injectors tested.

 

How is the blowby?
do the oil filler cap test.
when the engine is idling, remove the filler cap and place back in the hole. It should not jump around excessively. If it does jiggle then there are other problems....

 

passes fine. No smoke and no jiggle. Thank you.

 

Definitely sounds like injector issues. And don’t think that just because they’re new, that they’re automatically good. So many bad brand new parts anymore, it’s shameful.

but get it before you wash a cylinder and take the engine out completely.

 

Ugh. Really hoped to never do that job again. Is there a way to figure out which injector(s) might be bad?

 

Well, maybe. Get an infrared thermometer. They are available for $20-30 almost anywhere, I got mine from Amazon. With the engine idling, take a temp reading on the exhaust manifold at each cylinder. If it is injector failure, there should be a significant temp difference for that cylinder. Good luck.
Back to morning brew . . .

 

Nice...I already have one! I'll give it a look this evening.