LBZ: Truck no starty

REDHOSS02

hard n heavy
Jan 14, 2009
280
0
0
F U im from TEXAS
Long story short, ran a mustang and stomped his ass. Problem is he probably made it home without breaking anything. At the next light he turned, light turned green and I left the light my truck wouldn't go past 2k rpm as I eased out of the throttle it would change gears. Got it home and slapped on the V2 couldnt read any codes other than coolant temp not warming (temp sensor) been throwing that for a while. I cleared the codes and the truck ran fine. Decided to do a wot run again to see if I could notice anything. Felt like it was starving for fuel but was still dumping smoke, but it did it again. Took it home and went to clear codes and was going to move my truck and it wouldn't start. Full flashed the ecm with the dsp tune and still nothing. Checked prime and it looses prime within 3-5 seconds. I pulled the hose off going to the CP3 and put my thumb over the line coming from the filter assembly and it help prime for over 30 seconds. My question is could the fuel be bypassing the CP3 and going straight to the tank due to a bad CP3? Any help would be appreciated.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,207
5,018
113
Phoenix Az
you need to watch rail pressure and see if its raising up to 3-4000psi. IIRC it takes over 2000psi for the truck to finally start. if its not, time to start back tracing and figuring out why you cant get fuel to the CP3 (bad o-rings in filter head, collapsed fuel hose, ect) and also do a bottle test to see if the FPRV is stuck open.
 

REDHOSS02

hard n heavy
Jan 14, 2009
280
0
0
F U im from TEXAS
If it is stuck open will shimming it solve the problem or race valve? If shimming it is better isn't there a sticky with the shim "how to"? I did it on my lb7 but don't remember it's been so long. Thanks guys!
 

REDHOSS02

hard n heavy
Jan 14, 2009
280
0
0
F U im from TEXAS
UPDATE!! Bottle test was negative, but when I primed the filter fuel spewed from the return line hose I pulled to do bottle test. So figured out v2 and logged. 6700 desired 103.7 actual. Looking for injection pump.