Just picked up a Lb7 for super cheap as a crank/no start. Previous owner claimed that it shut off going down the road, threw a couple of parts at it then parked it. I threw some batteries in it and a scan tool on it and got no codes, turns over over fine, has crank signal, it has a new Air Dog 2 pump/filter on it and when on system seems to be primed, according to the scanner it is reaching desired fuel rail pressure when cranking and i can smell fuel just not out of the tail pipe, valley is dry so I dont think the CP3 is leaking. My question is, will bad injectors cause it to just shut off and not start?
LB7: Crank no start.
- Thread starter HD4ME
- Start date
Not unless they were really bad. And you would have other symptoms. Did you purge the fuel system so there is no air in the lines? How do the hard lines to the injectors look, maybe a little loose? Have you check the ecm with a scanner and seen if it displays the vin or jumbled digits? If everything checks out get some ether and spray it in the intake after the filter and see if it fires. If it starts let it warm up and pull rates off it. If there is an indication of any motor issues, like contaminated oil and such, do a compression check.
2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, Rick Fletes Dsp 5 on v2, 33x12.5 nitto at on 20 inch American Racing 20x10 wheels, Stage 5 Built Transmission by Mike Cole with triple disc billet low stall converter, 4 inch Injen cold air intake, Profab Intake Horn, Batmo Wheel, PPE Race Valve, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust axle dump, lbz cp3 pump, Dual Platinum AGM Duralast, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Upper Contol arms, Drilled and Slotted Rotors on all four Corners, FED Y Bridge, Shantz Custom Fab Traction Bars.
2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, Rick Fletes Dsp 5 on v2, 33x12.5 nitto at on 20 inch American Racing 20x10 wheels, Stage 5 Built Transmission by Mike Cole with triple disc billet low stall converter, 4 inch Injen cold air intake, Profab Intake Horn, Batmo Wheel, PPE Race Valve, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust axle dump, lbz cp3 pump, Dual Platinum AGM Duralast, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Upper Contol arms, Drilled and Slotted Rotors on all four Corners, FED Y Bridge, Shantz Custom Fab Traction Bars.
DON'T USE ETHER!
If you even think about a can of ether, disconnect the glow plug controller. Then throw the can far far away.
Get the scan tool back out, look for commanded injector pulse, and see if it is even trying to fire the injectors.
If so, look for a mechanical issue.
If not, look for an ECU or sensor issue. Check for cam signal too, not just crank.
And don't use ether.
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If you even think about a can of ether, disconnect the glow plug controller. Then throw the can far far away.
Get the scan tool back out, look for commanded injector pulse, and see if it is even trying to fire the injectors.
If so, look for a mechanical issue.
If not, look for an ECU or sensor issue. Check for cam signal too, not just crank.
And don't use ether.
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If you are getting missed cam counts, you have a sensor or wiring issue. I can drive 10 hours straight and never get one missed pulse.
I'd start there.
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I'd start there.
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Yes bypass, I’m assuming you checked all the big things before posting it. Have you put a reader on it yet. You need to make sure it’s totally purged of air in the lines after the head if it is still installed. Number one cause of no crank no start I have gotten.
2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, Rick Fletes Dsp 5 on v2, 33x12.5 nitto at on 20 inch American Racing 20x10 wheels, Stage 5 Built Transmission by Mike Cole with triple disc billet low stall converter, 4 inch Injen cold air intake, Profab Intake Horn, Batmo Wheel, PPE Race Valve, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust axle dump, lbz cp3 pump, Dual Platinum AGM Duralast, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Upper Contol arms, Drilled and Slotted Rotors on all four Corners, FED Y Bridge, Shantz Custom Fab Traction Bars.
2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, Rick Fletes Dsp 5 on v2, 33x12.5 nitto at on 20 inch American Racing 20x10 wheels, Stage 5 Built Transmission by Mike Cole with triple disc billet low stall converter, 4 inch Injen cold air intake, Profab Intake Horn, Batmo Wheel, PPE Race Valve, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust axle dump, lbz cp3 pump, Dual Platinum AGM Duralast, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Upper Contol arms, Drilled and Slotted Rotors on all four Corners, FED Y Bridge, Shantz Custom Fab Traction Bars.