losing power on hard pull

[Chamberpains]

(11-15-2019 )tdawg Wrote:  jakes jump up to 28 and then comes back to 15.

If this drop happens fast and/or intermittently and NOT after a long lessening jake downhill (15 psi can be normal 3rd stage at low rpm 1300 or less on slight down grades) then this strongly points to a faulty turbo actuator control module. It's the red box with an air line in and out and a 3 wires in to a plug under the air compressor on the driver side of the engine. If you can get you hands on a known good one and swap them out for a good long test drive, it would be the cheapest simplest way to know if this is the culprit. They are expensive $900 part and if it needs replaced you definitely want to buy 100% new GENUINE HOLSET.

[Evotrucker]

I've got a cm870, as chamberpains has stated maybe its leaking out of the turbo actuator module. i had to replace mine a while back. get some soap and water, spray it down and see if its leaking. its below the air compressor or in that general area.

report back to us when you get the chance. were all curios.

good luck dude.

[Chamberpains]

I'm actually saying the electronic solenoid may be faulty and commanding the actuator to different places other than where the ECM is saying it should be. It may or may not leak air. I had 2 fail electronically and 1 fail with an external leak. The electronic failures are hard to find. Monitoring boost levels on power and jake is one way to see it.

Rawze has used CT to override the ECM and command the actuator to a set point. Then measured the physical actuator travel to see if it in the appropriate spot.

[tdawg]

I was wondering about the control module myself. Don't have leaks on it but will check it.

[shawnkw]

My VGT accuator went out going east/west in arkansas so it had some real minor hills. nothing really to speak of. But when she went I was done turbo started chuffing and I was at a major derate. like mentioned above please check the VGT accuator


Good luck

[tdawg]

Changed the turbo control module but nothing changed. Coming home last night I put in some diesel kleen and truck was the same maybe a little smoother. After about 300 miles it started losing more power and got down to 20 pounds of boost and very low power. Got home and at idle davco filter has a lot of air bubbles. Still no codes.

[tree98]

You might have low boost because you have low rpm. When this low power condition occurs have you tried taking it out of gear and revving the engine to see what it does? Have you checked fuel pressure?

[tdawg]

Just checked fuel pressure and at idle its jumping from 210 to 270 very fast reved up to 1500 rpms and stays on 260. turned the truck off and ignition back on and lift pump is at zero pressure. Or do I need to check the lift pump pressure at the top?