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No fuel no start

Chevk587

Chevk587

Whiskey bent & Hell bound
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okay just got done wireing my 87 k5 with a stock 5.7 tbi no trouble codes except 12 . Fuel pump is on when key on , fuel is flowing through filter checked that . The injectors are not opening . I checked and there’s no signal from the ecm , the esc/icm is good . Lost any ideas what to check next ? Truck was running before this wireing was a mess that’s why it was replaced any input would be greatly appreciated.
 
Chevk587 said:
okay just got done wireing my 87 k5 with a stock 5.7 tbi no trouble codes except 12 . Fuel pump is on when key on , fuel is flowing through filter checked that . The injectors are not opening . I checked and there’s no signal from the ecm , the esc/icm is good . Lost any ideas what to check next ? Truck was running before this wireing was a mess that’s why it was replaced any input would be greatly appreciated.
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You sure you wired everything right?
I changed the wiring harness on my big rig and the new harness had 2 wires crossed it would never fire.
Injector wire from the ecm wasn't working, had to retrace every wire, 70 of them to figure it out.
 
Chevk587 said:
okay just got done wireing my 87 k5 with a stock 5.7 tbi no trouble codes except 12 . Fuel pump is on when key on , fuel is flowing through filter checked that . The injectors are not opening . I checked and there’s no signal from the ecm , the esc/icm is good . Lost any ideas what to check next ? Truck was running before this wireing was a mess that’s why it was replaced any input would be greatly appreciated.
Click to expand...

Pump shouldn't be running with key on, unless you are talking about the couple of seconds of priming that the ECM does when key is first turned to run? Just want to make sure, since you said it's rewired.

Injector opening is indicated to the ECM by receiving a pulse from the distributor module, which should also turn the fuel pump on.

How did you test injectors? I assume you watched for fuel, but you have to use a test light (not multimeter) across the two injector wires, not grounding one of the leads to the test light.
 
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dyeager535 said:
Pump shouldn't be running with key on, unless you are talking about the couple of seconds of priming that the ECM does when key is first turned to run? Just want to make sure, since you said it's rewired.

Injector opening is indicated by the ECM receiving a pulse from the distributor module, which should also turn the fuel pump on.

How did you test injectors? I assume you watched for fuel, but you have to use a test light (not multimeter) across the two injector wires, not grounding.
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Got you that makes sense the ecm grounds the injectors I’ll try that a gmc make sure . Yes just the prime for a couple seconds.
 
dyeager535 said:
Pump shouldn't be running with key on, unless you are talking about the couple of seconds of priming that the ECM does when key is first turned to run? Just want to make sure, since you said it's rewired.

Injector opening is indicated to the ECM by receiving a pulse from the distributor module, which should also turn the fuel pump on.

How did you test injectors? I assume you watched for fuel, but you have to use a test light (not multimeter) across the two injector wires, not grounding one of the leads to the test light.
Click to expand...
Definitely no ground signal coming from the computer
 
Chevk587 said:
Definitely no ground signal coming from the computer
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Then it's likely the ecm isnt seeing the pulse from the distributor for whatever reason. There should be some "crank no run" charts you can find, or go to to the link in my signature and the proper year service manual should cover it.
 
dyeager535 said:
Then it's likely the ecm isnt seeing the pulse from the distributor for whatever reason. There should be some "crank no run" charts you can find, or go to to the link in my signature and the proper year service manual should cover it.
Click to expand...
Talked to painless today they are say I’m loseing power to the computer when cranking so they are suggesting finding a different power source for the ignition. Also mentioned a pass key / pass lock anyone know anything about that ?
 
I don't think 87 had passlock or passkey.
My 2001 Tahoe has passlock2.
It consists of a hall effect sensor in the ignition switch.
The computer senses whether the ignition has been tampered and cuts fuel to the injectors.
Passkey has a resistor built into the key that is read by the ecu everytime the key is put in.
Both sysyems are somewhat failure prone.
And they will cause no fuel to the injectors.

Maybe someone here knows better but I don't think passlock/passkey came out till the 90's
 
K5wrench said:
I don't think 87 had passlock or passkey.
My 2001 Tahoe has passlock2.
It consists of a hall effect sensor in the ignition switch.
The computer senses whether the ignition has been tampered and cuts fuel to the injectors.
Passkey has a resistor built into the key that is read by the ecu everytime the key is put in.
Both sysyems are somewhat failure prone.
And they will cause no fuel to the injectors.

Maybe someone here knows better but I don't think passlock/passkey came out till the 90's
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Correct.
No square I know of got that
 
Thanks just wanted to make sure I didn’t think It did.
 
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