I have a 2001 lb7 that I just put back in my truck. It got new heads, head studs, airdog 160, new injectors, and glow plugs. I got it back in and she'll crank all day but no start. I'm not getting enough rail pressure to start. I think I read somewhere that it needs 4000psi to start? I'm leaning towards a bad fca. Would that make it not start? I pulled the return to tank line off and it seems to be returning alot more fuel than it should. I do have a gauge that reads 13 psi to the cp3 from the airdog. Any ideas?

 

has it set any codes, maybe something got left unplugged somewhere.

 

no codes. I've checked the cam and crank sensors. They do come up when i unplug them. Maybe my fca is sticking?

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Anyone know the wiring on the fuel pressure sensor. The guy I bought it from decided the plug on the harness needed to be cut off. It now has crimped on spade connectors stuck in the sensor plug. Who knows if they're right or not.

 

if it not right it wont start

 

What are all of the possibilities for no rail pressure? cp3, injectors, fca, fprv, loose or cracked lines. Anything else?

 

did you have the cam and crank sensors out of the engine? Are you sure they didnt get swapped around when the were reinstalled? What rail press. reading are you getting? should show like 1-2mpa koeo.

 

yeah, it's an lb7. i have a lift pump with 13 psi feeding cp3 is confirmed with gauge in line. The truck will crank but not start so balance rates are out. I guess a return test is next? Could the fca just be bypassing too much fuel if its stuck?

 

nah the fca just regulates fuel, any bypassing would be done internally in the cp3 pump by the cascade valve. if you have a scanner make sure the rail press. is 1-2mpa with koeo. That way you know your sensor is reading right. Could you have possibly mixed up the cam and crank sensors?

 

I didn't take out the cam/crank sensors. I can unplug them and a code comes up for them and I can clear it once I plug them back in. My fuel pressure sensor is fried I think. It's stuck on 26.1kpsi. The only way I have to read some of my info is a CTS. I'm just waiting on EFI to come down a couple hundred bucks!haha! The injectors are brand new.

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Does the fca regulate the fuel from 0 to 100 percent? And does it do this by adjusting voltage to the regulator 0 to 5volts?

 

if you unplug the pressure sensor connector or have a bad connection it will read max PSI. stock max is something like 23K psi, 26K+ psi sounds like some rescaling was done and/or lbz parts where used ie: cp3, regulator or sensor (it will still read 23k psi with out rescaling). if this is the case then you may want to investigate the cp3 and see if something was not done right there