Fuel pump

tatey2457

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Having trouble with my fuel pump. The grey wire that powers the pump is going to ground, I turn the key, get 12v and the pump primes but then when it stops it goes back to ground...bad pump? I've traced the grey wire back to the pump and it's not shorting anywhere.
 
what do you mean the wire is going to ground? Is a fuse blowing? You do know there is a relay in the circuit?
 
No fuse is blowing, relay is good...tried swapping it for a known good one. turn the key to run and the grey wire gets 12v, the pump primes. That grey should keep battery voltage for the injectors but it grounds...I dont know if its the pump or if the pcm or passlock is grounding the wire to prevent the injectors from pulsing...I've tried two ign cylinders and a spare pcm and cluster. It has spark and compression but no injector pulse.
 
So...I checked the passlock harness and there is resistance on the ground...where in the cluster does this ground go?
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Check for voltage when the engine is cranking. The pump will prime, then nothing till it sees a tach signal. The injectors should be on a seperate circut than the pump.
 
Check for voltage when the engine is cranking. The pump will prime, then nothing till it sees a tach signal. The injectors should be on a seperate circut than the pump.

From what I can see on the diagram, the injectors all share battery voltage with the pump then get grounded by the pcm injector driver to make them pulse. My thinking is that the pcm is either getting no password or not getting it in the required time window and then shutting down the pump/injector

I'll check for voltage but what should I be checking...7X Reference Signal? I get good spark when cranking.
 
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