LML Lml high rail pressure

[quinton]

Got 2011 lml I just built with a 12mm cp3. Another guy installed the motor and crossed the rail sensor plug with the FPR plug. He said got a new FPR and installed it and never plugged it in. Well after I swapped em I got the truck running but it's maxed out on rail pressure plugged in or unplugged. With key on purple wire to FPR gets 8.4 volts. When watching scan tool it's commanding 6k psi and can see FPR % change while plugged in. With truck off key on I can clear the p2294 code but immediately comes back on with reduce power mode. Any ideas? I've only messed with it for about 30 min so far, while he has over 30 hours in trying to get it to run..

 

[quinton]

Well I got the truck to start now at 6k rail pressure then after a few seconds it shoots up again to max pressure. When it's at 6k it kinda bounces and runs rough. No smoke though. Any ideas?

 

[IOWA LLY]

Have you tried replacing the pressure regulators again? Maybe having them unplugged, and the high rail pressure spike damaged them..... I don't know its just a thought.

 

[quinton]

Yes I did yesterday. I tried the new and old one same thing happens on both. Starts off good, then shoots up. Anyone seen stuck injectors cause this?

 

[quinton]

is there anyway the 12mm cp3 could cause this issue?

 

[FSUwelder1212]

I could be way off but have you tried replacing the rail pressure sensor? I'm a newb but I would think the FPR would run off a higher voltage than a sensor which is likely just 5v reference, and crossing could have fried the sensor.

 

[quinton]

Yes I actually just did that no difference

 

[FSUwelder1212]

I wonder if it could've fried the driver in the ecm for the FPR?

 

[quinton]

Well figured it out. Wire was bare and I guess shorting out. I rewired it and it's good now.

 

[IOWA LLY]

Awesome! Glad to hear it.


Sent from my iPhone using Tapatalk Pro