HELP! NO INJECTOR PULSE,...non running 96 suburban tried everything

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corbin dallas

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hello. i will try to give you overview,..need some help. my 96 suburban with stock vortec 5.7 crab injection. truck ran fine,..then started to skip and run rough especially after startup warm or cold. then smooth out after 1 mile. hard code of p01345 crank/cam correlation. also was running 28degrees timing and had misfire codes, mass air meter out of range, o2 sensor and lean codes. so rplaced mass air. no change, replaced distributor. double checked installation and made sure no slack in timing chain-no change. replaced crank sensor,..no change, replaced fuel punmp,..no change. then one day it sputtered and stumbled up the driveway and shut off. never ran again. checked injector pulse and nothing(not grounding),..got new computer and sent out to reprogram,..stil no run and no injector pulse. HELP!!!!!!!
 

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Recheck engine grounds. Look in top of upper intake and see if 2 of the big oval gasket installed.
Unplug injector harness, test for power and ground on harness back to computer. A 194 bulb works good with alligator clip wire here. Computer is 5 volts. careful.
 
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corbin dallas

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Recheck engine grounds. Look in top of upper intake and see if 2 of the big oval gasket installed.
Unplug injector harness, test for power and ground on harness back to computer. A 194 bulb works good with alligator clip wire here. Computer is 5 volts. careful.
truck has multiple chassis and engine grounds(more than just the stock grounds,..but I will recheck). the upper and lower manifold gaskets are new and double checked. there is power at the plug to the injectors but NO grounding of the injectors(non of them) from the computer/harness. the computer is new and flashed for the suburban,..i also have the stock computer and same issue,..no injector ground so no pulse. checked with node light
 
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corbin dallas

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did you test the icm (ignition control module)?
I have not since I would suspect it would have noting to do with the harness to injectors not producing a ground to fire the injectors. am I wrong to assume that? i found a test procedure on her for icm,..but I think I have another one I can swap in and see. i will get back to you guys. thanks
 

OR VietVet

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You said replaced distributor. What came with it? Module? Pickup coil? Cap? Rotor? Brand? Tested coil?
 

exp500

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Ref post 4- Disconnect harness at both ends, check ground wire continuity. may be replacing a wire there.
Also test computer pin for ground when cranking. Hope you bought a factory service manual for pin /wiring layouts.
You will need a small connector like a butt splice for 22 gauge to get your meter connected to computer pins.
Lastly- Do you have a theft light flasing on dash? Does the light lite up when key on not started?
 
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corbin dallas

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You said replaced distributor. What came with it? Module? Pickup coil? Cap? Rotor? Brand? Tested coil?
yes new distributor. installed correctly. old distributor was probably fine as well since there is no shaft play,..but still no change. new cap rotor plugs wires.
 
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corbin dallas

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Ref post 4- Disconnect harness at both ends, check ground wire continuity. may be replacing a wire there.
Also test computer pin for ground when cranking. Hope you bought a factory service manual for pin /wiring layouts.
You will need a small connector like a butt splice for 22 gauge to get your meter connected to computer pins.
Lastly- Do you have a theft light flasing on dash? Does the light lite up when key on not started?
all harness wires look fine. trying to get a diagram to see what wires are for ground,..but can identify and chase each one from plug,..but all 8 have no ground pulse so doubt it is just one broken wire,..impossible for all 8 to just go bad. any ideas where to get pin diagrams? this is a 96. no anti theft at all
 

Doubeleive

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I have not since I would suspect it would have noting to do with the harness to injectors not producing a ground to fire the injectors. am I wrong to assume that? i found a test procedure on her for icm,..but I think I have another one I can swap in and see. i will get back to you guys. thanks
I am not sure but the problems you described fit in with a bad icm
 

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