Whats up everyone, got a f450 givin me some trouble. I can start the vehicle when it is cold and it will run for aproximately 15 to 25 mins. During this period, high pressure oil is fluctuating between 470 and 500 psi. Have replace the icp and removed the ipr, resealed and cleaned it. It still does the same thing. Performed koeo test and code p1283 ipr circuit failure. No metal flakes in oil, have wiggled wires while trying to start and while it is running and nothing causes it to die. When the vehicle dies, the high pressure oil falls to 25psi and stays at 25psi even when the engine isn't running. Then while trying to start it again, the oil pressure will not exceed above 200psi during cranking. Give the truck 30mins and will start again. And i also noticed the coolant temp on the computer was fluctuating between
5f to 520f which is crazy. I looked for the coolant temp sensor for the computer and couldnt find it anywhere. I talked to someone and they said it didnt have one but i looked on alldata and it says it has one. I am offically stumped. If anyone has experienced this problem or similar please let me know what you did to solve this problem. Thanks Everyone

 

It sounds like it either has a problem with the ipr staying completely open or the HPOP is bad. The old engine in the boss's 02 f250 had a bad oil HPOP and you could be driving along and the high pressure would drop off from 1500 at cruising to 500 or less and it would lose power or stall.

 

the ipr valve assembly is in good condition but i am unsure of the magnectic coil part it. i think spec is 15-20 ohms but i didnt check it. i found the spec after working on it.

 

Coolant temp gauge should be mounted on the front of the motor near the thermostat I think. As for your issue, I would work from the sensors back the the PCM and look for chaff points where the wires could possibly ground out. Next, hows your lube oil pressure? If the low pressure oil pump fails, it can't feed the high pressure pump. ALso, double check your oil level. Seen that more than once. . . . .

 

bad injector o-rings?. idk

 

Good thought but typically orings will allow it to start cold and run fine, but on a hot restart when the oil is thinner, it will hard start.