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Black Smoke and low power at low RPM

8479 Views 25 Replies 7 Participants Last post by  JazzBass
This has been on going for a couple of summers now. When things get hot, pulling away from a stop or accelerating in OD, the truck smokes and feels quite lazy and the boost seems to lag what my foot is requesting. The heavier the load the worse it gets and the hotter the outside temp the worse. It basically goes away in the winter. It will do it when bobtailing after a long run on the freeway then come to a stop sign on an off ramp and start to pull away.

EBP, IPR & ICP have all been replaced recently as has the FICM and 8 injectors. I just replaced the hose running to the MAP sensor before the last trip and removed the EBP to recheck and clean, it was in good shape. The EGR was replaced last summer but didn't fix it, it has been cleaned several times since. The truck runs like it did when it was brand new until this issue happens then it's fine again once the truck cools down.

Once back in April, in the mid west I was pulling into a 40 mph headwind mostly uphill and working the tail off the truck, the boost would wail up to the 30 psi mark, I would lift, it would race down to the bottom then get stuck at about 5 PSI and I would have trouble picking up speed, the truck would drop a gear, RPM up then it would start working fine again.

I've had the turbo off twice and taken it to a diesel shop, they've opened it up, lubricated it then handed it back telling me everything looks good.

I also data logged yesterday but it was just while I was rolling along without a smoking issue. I have attached a couple files. I used the CTS2, not as thorough as my AE but much easier to do spur of the moment. Yesterday, I was on secondary 2 lane roads later in the day which I seldom drive on and pulling away from stop lights with trailer, it smoked heavily until it got rolling then nice and clean.

I even passed the snap test for emissions testing a few days ago.

I have a 2 hour run tomorrow morning with a trailer on but it will be fairly cool and and mostly 4 lane high speed but I will data log again if it starts smoking.

I'm ready to order a brand new OEM turbo (Garrett has new ones now...brand new) but I would like to know if there is anything else I can check first like maybe the VGT solenoid, is there a test for it?

Any ideas please before I just throw a turbo at it?



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You need a good scan tool that is thorough at pulling codes.

Highly recommend ForScan Lite on a smartphone with the appropriate OBDII adapter for the brand of phone you have.
Wow - thanks for the recap.

I can't recall, are you tuned? Also, what year model engine?
Have you tried cleaning the MAF sensor (using MAF cleaner spray or electronics cleaner spray)?
Let us know how it drives after the MAF cleaning.

Do you know if the EGR valve that was installed was OEM or aftermarket?

I can't recall - did you check all the temperature sensors after the engine has been off overnight? They should all be fairly close (IAT1, IAT2, EOT, ECT, TFT)

Also, at KOEO are MAP, Baro, and EBP all reading within say .5 psi of each other?
Was that 92 degree reading at the same time as the 80 degree readings on the other sensors?

If so, then yes, it is bad.,,,,,and you are correct IAT (or IAT1) is part of the MAF sensor on the engines that have a MAF sensor (some don't).
What the heck is the difference between an EGR delete and an EGR eliminator!!??
1 - 5 of 26 Posts