No acceloration

[460+]

I have a friend who has an 08' f350 dually ex cab 4x4 6.4 with a auto trans.His complaint is when pulling a trailer or empty, his truck will be running fine then it will go into a limp mode and will not accellorate or act like the accelorator pedal does nothing. If he shuts the truck off for about 5-10 mins he can start the truck and it runs fine for a few miles then does it again. He hauls trialers from Indiana to Florida and some other states down south. He has taken it to the dealers down south and they have scanned it and installed sensors for the high psi fuel pump or something to that affect. He's not for sure. This last trip it got worse so he took it to a local dealer up here, wich it didnt act up for them, and they couldnt tell him what was going on. Sorry for the long post any help would be greatfull

[forddieseldoctor]

He needs to monitor eot and see how high it's getting. I had a work truck that did the exact same thing. I finally took it out on the interstate and shifted into a lower gear and pegged it at about 3000 rpms. After about 5 miles the eot hit 260* and the truck went into limp mode.
There is a recall that was released within the last few weeks. It is for a reflash on the 6.4's. The new reflash will throw the temp gauge high when the eot hits about 250*. I would recommend having him take it in and have it flashed. Then if it is the eot that is going high it will give warnings in the instrument cluster.

[460+]

Thanks, I will let him know and give it a shot.

[forddieseldoctor]

Okay I finally found the actual specs for what temps it derates at:
• ECT — Derate will occur when the engine coolant temperature is greater than 113°C (235°F)
• EGRT_A — Derate will occur when temperature is greater than 705°C (1,300°F)
• EOT — Derate will occur when the oil temperature is greater than 126°C (259°F)
• FRT — Derate will occur when temperature is greater than 90°C (194°F)

[1tonpower]

My truck did it. Seemed worse when it was wet. I beleave thy put a new peddle in and found a shorted wire

[460+]

Thanks forddieseldoctor, hopefully these will help. I let him know about the eot. He was leaving today and he said so far no problems.

Thanks 1tonpower, did yours set a code for the pedal?

[1tonpower]

it was throwing code but i cant remember what it was.. it happen when i was 3 hours from home. that god i had my scanner with me. i had to keep clearing the codes to make it home. some times it would go 5 miles other times would go a hole day.

[460+]

So far he has no codes for that.