I thought I'd ask this here before the SD crew as the sharpest hang out over here.

pre 99.5 CCLB auto DRW

Initially brought to me as it was communicated it was cutting out and gutless. Short and sweet the plenums were resealed, rebuilt turbo/billet wheel, new boots and a new MAP, truck went from 9 psi to 23 in stock form. I had my computer plugged in the short time it was in the shop and test driven, never hiccuped. As soon as he plugged in the edge insight it was cutting out anytime when whacking the throttle. Since then that has been removed.

Fast forward a month to today. Truck is returned and gutless, had a 1211 and 1209 stored. At cold idle icp and IPR DC are in check. It's torquey is as it should be down low when on the throttle and then it falls in it's face as RPMs go above 1800. I can spin the dual tires on dry concrete brake loading up till 2200 and then nothing. It weird it like the power transfer stops and the motor still spools up and builds terrific boost.

Niw here is the part I am questioning, once it warms up a tad the D.C. Goes through the roof, 40% to hold idle pressure -480, peaks at 65 anywhere on the throttle AND ICP FALLS OFF AFTER AN INITIAL SPIKE. When accelerating the ICP pops to 2200 psi down low then sits below 1000 at wot and 65%, the part that has got me is the truck is making 23lbs of boost... and is not moving. I don't understand how it could have such poor oil deliver and appear to be fueling very well and building terrific drive pressure and boost. It has been verified Mechanical and at the MAP sensor. Due to what I'm seeing in oil I'm going to replace the IPR, the internal plug on the shaft is loose as it is. Seen it dozens of time without ill affect but either way, i'll replace it. Im going to try this before popping the valve covers and looking for a oil dump whether injector or orings. I can't imagine the pump crapping the bed instantaneously. Truck made terrific pressure on a stock pump a month prior.

I am asking for your thoughts on the issue with oil, which is the opposite of what I'm seeing with boost... usually they go hand in hand and are not polar opposites.

Secondly if the truck is making that much boost at 3k and is a turd, it sure seems the TQ converter is shot? What else could it be? doesn't matter the gear but if you are pushing that much drive force and not moving.... it's all I can think of, yet the OD is not flashing.

Its an odd problem I have not seen before in this sequence. I have never seen a boost number like that, no oil, and the truck that is a turd in putting the power to the ground.

icp is dry... i can swap if need be


a healthy 7.3 at this altitude puts 18-21 psi on fresh everything in stock form data logged in AE, his motor had healthy compression when purchased and the charge intake has been tested to 60 psi and turns the motor over.

 

I'm in the same boat as you with my work truck, same exact symptoms. Following along, the guy that rebuild my tranny said its a voltage problem not allowing the solenoids to work properly allowing pressure to escape? I verified voltage to vehicle and right at 14.3 I still haven't checked voltage from pcm to tranny thou.

I can only explain this like this:
If im going say 55 mph, and do a WOT run down shifts to 3rd rpm's shoot up to 3K but truck won't pull you hear the engine scream, boost at 21 psi, it's after I back up the pedal a bit and try to achieve what I believe is the TC to lock that's when it finally begins to pull.a stock Obs can run circles around this turd.

Stuff I replaced to trouble shoot even thou they are good parts.

Pedal assembly

Tranny rebuilt due to front seal leaking and having almost 400K at the time.

Replaced and and clean in tank strainer and shower head

Fuel pump stock one had great pressure but for trouble shooting purposes I got a new one

Rebuild the fuel pressure regulator

New IPR and ICP

HPOP and injector Replaced both were working great, HPOP I stripped the fittings for the pump, injector I needed a spare set because the other trucks at work.

Only pending codes are upper and lower Alternator faults, my gut tells me it's the PCM that took a dump.

 

I can understand the 1211 with only 1000 ICP but IDK the rest. Subscribing

 

Your trans guy should be able to verify the voltage before you throw more parts at it. That's the plan with this if it keeps up... Their scanners can tell them just as much about whats going on inside the trans as we can see with any computer or mechanical sensor on the drive side.

Yeah I doubt its something simple...