I've tried almost everything to get this truck to rev higher than 4500rpm. Truck has headers and gen 3 mustang intake mani, other than that its stock. Truck came to us from another shop with the issue and no idea why it started. Supposedly it ran fine at the track and sat for a year waiting for turbo build that didn't happen and started issue when he picked it up after putting a new battery in it. It will allow any RPM at part throttle but will cut fuel above 4500rpm only at WOT.
Never seen this before on identical trucks/mods. Something seems different.
We reprogrammed PCM to stock twice doing any new updates through Ford software, no change, replaced PCM and reprogrammed all modules again and nothing changed.
The truck should technically run pretty good without any changes to the tune other than maybe reconfiguring IMRC scales.
With Mustang or Truck IMRC settings it still cuts at 4500-4800rpm. Nothing shows up in a log as a limit, the truck just hits a wall and reduces injector PW.
If I disable all IPC related control/reports as a test it does the same thing on the street, UNLESS I PUT THE TRUCK IN DYNO MODE AND STRAP TO DYNO THEN IT WILL RUN AND SHIFT AS COMMANDED.... If you unstrap it making 0 changes and make a street hit the issue is back again. As a test I strapped it to dyno, made WOT hit with no issue, never killed the truck, unstrapped it and floored it in the driveway, issue is back again. Almost as if its wheel speed related.
So, went back on the dyno and calibrated wheel speed data to make speedo and Dyno speed read identical, verified with GPS on road and issue still there didn't change anything.
I attached the file and log in it right now. Its basically stock with mustang IMRC data, fuel cut limits raised, Trans limits raised higher than needed. The truck should be capable of running the factory shift points in this file without any other changes since its pretty much stock.
Any Ideas?