Just got done with my built motor and got it installed the truck. Fuel wise it's a 10mil pump, lds 45% injectors, brand new gm lbz regulator. The first issue we ran into was the truck would crank for 3 seconds and quit it did this over and over until we unplugged the engine harness and plugged it back in. Then we got the truck to crank until start. It instantly went to 26k psi rail pressure and had a cam sensor code. Anyone have any idea what would cause this?
LLY: 26k psi at idle?
- Thread starter wfc09
- Start date
You cam code was why it would only crank for a few seconds. It wasn't getting a signal from the sensor. If the cam sensor or crank sensor are unplugged it will only crank for a few seconds.
You prob have a couple issues with your engine harness.
You prob have a couple issues with your engine harness.
We swapped the short harness from the main harness to fpr. I'm going to check the pins in the bale connectors after work. One thing we noticed was the plug for the harness was getting 11.5 volts isn't it supposed to be getting 5ish volts? Could I have something back feeding?
The fca runs on battery voltage, not 5 volts. One pin should have battery voltage present, the other is controlled to ground via the ecm to regulate pressure. Have you retuned for the lbz regulator yet? If not, start there provided you have power and ecm controlled ground to the regulator(real easy to tell if you do, does the regulator buzz/humm with the key on).
The truck is tuned for the lbz regulator. We even swapped the ecm to make sure that wasn't it. The regulator does buzz with the key on but not all the time. We have another harness I'm thinking it may be time to just swap out the harness and see if that resolves the issue
I had a modified lbz reg bad right out the gate. Pulled it and stuck a stock one in and was fine. Did the same as yours, went to 26k right at idle.
that says alot about the issues you are having. i would be looking to make sure your pins are connecting correctly.
Backprobe with it running, and see what voltage you have at the regulator. It could also the ecm as the power goes from I believe the eng-1 fuse to the ecm, then back up to the fca.
I will check that tomorrow. I swapped the harness today n got no where going to try and get the schematics/pin diagrams for the truck side of the harness and check it out also.. if any of you all have these I'd greatly appriciate it if you could send them to [email protected]
OK so I've changed the entire harness, swapped ecms, Unpinned the ecm connector, checked voltage which is a 12 volts at the regulator still doing the same thing. One thing I noticed is if I unplug the connector nothing changes but when I plug it back in the rail pressure will drop down to 19,000ish psi and then right back up any ideas? Bad regulator? Bad pump maybe?