08 F350 Lacks power at times

forddieseldoctor · September 18, 2020

I got an 08 F350 with the magnificent 6.4 in it. Every once in a while it falls on it's face coming out of a stop sign. Sometimes it feels like a stuck turbo on a 6.0 (a little laggy off the line, but will pick up at higher speeds) and sometimes it won't go over 10 mph until you pull over and try again. It has a P2263 for turbocharger boost performance. I verified that the vgt stay at 95% most of the time while driving and the ebp actual pid is way too low compared to the ebp desired pid. The customer had a pair of internet special turbos put on about a year ago and both the ebp sensor and tube were replaced while chasing this concern at another shop. But I found another interesting thing when I left a stop and couldn't get over 12 mph on the flat at half throttle. It gets very hollow sounding and the cackle noise goes away completely. And I noticed in the recording I made of it that the TQ_CNTRL pid is cycling rapidly from "none" to "tip in throttle". I stopped on the side of the road to change datalogger over to trans so I could look at the speed sensor readings I never put it in park, just sat with my foot on the brake and when I took off again it was done acting up. I looked back at the other recordings I made earlier in the day and verified that when it had the noticeable lack of power it had that pid cycling then too. I inspected both speed sensors on the trans and I don't see any obvious rust jacking on them. I performed ppt KA and it's telling me to inspect and replace the turbos as needed, but I really don't think that's gonna fix the bigger issue at hand.

Anyone got any input on what is causing the pid to cycle? I'm currently waiting for hotline to get back to me.

8WA Sman · September 19, 2020

Maybe Brad can shed some light on this??

I am guessing you checked tune and PCM updates?

I would also look at TCM software and pids to see if anything jumps out.

forddieseldoctor · September 20, 2020

Truck appears to be bone stock. I got another recording. This time I was cruising at 45 or 50 mph and came to a hill and tried to maintain speed and it fell on it’s face for a couple seconds till it downshifted. Game plan for Monday is to remove and inspect ebp, map sensor and clean maf sensor. Along with check air filter just for giggles. I did monitor the trans pids along with the egt and egrt pids. Everything looks normal to me.

Hotline was no help what so ever. They told me that since ppt ka said it needs turbos to put turbos on and retest. 🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬 I didn’t feel the need to even bother wasting my time on the phone with them to try and get anything else out of them.

Brad Clayton · September 20, 2020

I got nothing unfortunately. I parted ways with that dealer a couple of days after that truck and don't remember the outcome.

I do however, have a truck acting similar and the cab is off getting up-pipes for major exhaust leaks. I don't have that warm and fuzzy feeling about it actually fixing the customers low power concern. I expressed this concern to management and the customer and they wanted the leaks fixed anyway.

I should have this thing running by Wednesday and if it acts just like the one in this thread, then I will have some input.........I'm hoping I don't though! :rolleyes:

8WA Sman · September 21, 2020

Maybe inspect the throttle body or pids. I don't remember if you can drive a 6.4L with the throttle body disconnected, may have trick the PCM into thinking the throttle valve is still connected.

Maybe monitor the fan clutch or drive with it disconnected???

I find TSB 08-16-02 interesting, I don't know that I ever thought about updating an IC at the same time as the PCM/TCM.