Ok, after completing shimming the Fuel Pressure Return Valve (PPE shim kit) on my friends 2005 LLY I jumped into the cab after putting everything back together and priming the system only to get the batteries tired on the first 2 attempts at cranking. So I hooked up the jumper cables to my truck (not direct to battery, but the jump location off the engine on the chevy) and let my truck run for a few minutes. After trying that and getting nowhere on 5 or 6 more start up attempts, his batteries where toast. Replaced his batteries with two new Optima Yellow tops and began to try starting again. All she does is crank and no fire! In-between every start up I use the prime on the fuel filter housing until it gets firm, and it will stay firm for at least a full minute and there isn't any fuel coming from anything, or no leaks I should say!

Long story short after attempting to start way too many times, my friend is in the car audio biz and completely disabled his Viper alarm just to play it safe, that still didn't work. Then I hooked up my cheap Actron Scan Tool so I could watch "FRP - Fuel Rail Pressure" and it will start to climb to about 375psi, then fall while cranking. We checked all fuses and Relays to find that the Fuel Pump Relay is only getting (1) constant power and no key on or crank on. So our supply to that relay isn't correct like the other relays, tried swaping relays just to try, same problem.

I left the batteries disconnected overnight last night and hooked them up this morning only to find the same problem. At this point we are under the assumption that when the batteries got almost completely dead, the VATS System is inhibiting the truck from firing...

Any ideas, please pass them down to me

Thanks

You are opening the bleeder screw right?? You have to open the bleeder and then pump to pull fuel at least into the filter.

You are opening the bleeder screw right?? You have to open the bleeder and then pump to pull fuel at least into the filter.

sound slike you still have the air in the system. You don't have a fuel pump so don't worry about that relay, it's a spare. like int he above post, pump the primer and then open the bleeder screw. Do that untill you get only fuel coming out. If you can not get fuel coming out then your problem is somewhere other then @ the motor. Once you do get a full stream of fuel out of the bleeder, close it and then pump a bunch more like you have been doing. Your fuel pressure needs to be around 1000 to start. Good luck.

Thanks for the input guys, but I have in fact bled the system numerous times to where fuel is all over the ground. Pump it up, crank the screw, and it comes out like a piss stream. I've given it my best and had my friends truck towed to Chevy for a deeper look. Not sure what is causing this problem after attempting more things since the last post, but I will find out soon enough i guess??

It may happens that your fuel pressure relieve valve is not function correct after the shim modification and stays open and the pump can't hold the pressure. Try the bottle test on the fuel return line on the FPRV. If you get constant flow (or any flow) than you have problem with it.

Any update on this? I am seeing the same thing. My injection pump is less that a year old. Can a bad pressure regulator do this? I have mine out and i can blow the the end and out the sides, so it is open like i thought it should be.

I also took out the high pressure pop off valve like the guy above shimmed and checked it, it seems fine but i have no way of being sure.

I got a 05 it wont start y did you shim the return i never herd of that

When you took apart the PRV you must of lost the little pintle in the end of the valve..

Call me

Dan
714-985-4825