LB7: Why won't it start!?
- Thread starter slipagnt
- Start date
It will crank before 4k , sure your not getting that mixed up with idle pressure ?
Built motor , duel fuelers , 60's overs , gtx4202r
Thought it was somewhere around 1000 to 1200 psi ?? Then they would fire , and then idle around 4500 to 5000 psi . Just asking here
Built motor , duel fuelers , 60's overs , gtx4202r
http://www.duramaxdiesels.com/forum/showthread.php?t=14795&highlight=Start&page=2
They don't need fuel to crank but you need a min of 4000 to run most trucks idle at 6000 but it will idle at 4000 no problem .... You are right about injectors opening but if he has 1200 even 1500 it won't start and I would guess bad inj or cp3
Read post 67 there is a good document from GM in there and the whole thread is good for the OP
They don't need fuel to crank but you need a min of 4000 to run most trucks idle at 6000 but it will idle at 4000 no problem .... You are right about injectors opening but if he has 1200 even 1500 it won't start and I would guess bad inj or cp3
Read post 67 there is a good document from GM in there and the whole thread is good for the OP
Like said, isolate injector banks and pumps if possible. Testing fuel return on injector banks and pump(s) as well. Both those tests are very time consuming though. It is possible to have air in the system from a cracked fuel line or hose, I've seen trucks run momentarily with a bad fuel hose. It would help a lot to see rail pressure and commanded fuel flow.
thanks for the help guys. I'll start easy and double check cam and crank sensor operation. then proceed to verify rail pressure. would a bad fpr be an issue?
Allright, Cam and Crank sensors check out. Now I'm leaning towards cp3 or fprv. Anyone know how to test the fprv?
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Truck will start with a bad regulator I've done it lots
Have you checked for stuck Inj yet?
I agree. It's in the future but not if I need a new cp3 or something. I've got no rail pressure. As a last resort I took off a high pressure line and got barely a drip while cranking it. I'm in denial with the injector thing. They're brand freakin new.
Yeah, it's hooked up just like that. I bought new hoses from GM when I built the motor cause the others were falling apart.