89 corvette odd injector pulse
Thread Starter
Intermediate
Joined: Jan 2022
Posts: 25
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89 corvette odd injector pulse
I have 1989 corvette burning out ecm.
injector pulse with no key on both sides green.
Both red with key on. It cranks then dies.
rebuilt engine, new injectors, new fuel pump, new fuel filter, new fuel regulator, new distributor, on third computer.
Any suggestions ?
injector pulse with no key on both sides green.
Both red with key on. It cranks then dies.
rebuilt engine, new injectors, new fuel pump, new fuel filter, new fuel regulator, new distributor, on third computer.
Any suggestions ?
Last edited by C_Vette89; Jan 2, 2022 at 06:23 PM.
Melting Slicks
Joined: Jan 2014
Posts: 2,192
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From: Lunenburg MA
Thread Starter
Intermediate
Joined: Jan 2022
Posts: 25
Likes: 0
Had wiring mechanic work on it, he was unable to fix. Ran for a week then died.
He said, it was burning out computer and points. Possibly ground out computer.
1250.00 later still not working right. All
injectors ohm at 16.4
He said, it was burning out computer and points. Possibly ground out computer.
1250.00 later still not working right. All
injectors ohm at 16.4
Melting Slicks
Joined: Mar 2001
Posts: 2,150
Likes: 304
From: Timra, Sweden
Ok, so it is this test light that indicate connection to +12V and GND with red and green LED.
Power to injector should have steady red light with ignition on.
ECM side of injector should be red with ignition on and engine not running. With engine turning over you should have both green and red indicating pulses from ECU. Might be difficult to see if pulses are short.
Power to injector should have steady red light with ignition on.
ECM side of injector should be red with ignition on and engine not running. With engine turning over you should have both green and red indicating pulses from ECU. Might be difficult to see if pulses are short.
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Burning Brakes
Joined: Oct 2017
Posts: 823
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From: Somewhere near Fort Wayne, Indiana
Both sides being green with the key off is interesting to me. I dont know if the ecm grounds when its off. If it does, that would be normal. Have you tried checking with the ecm unplugged?
Are you sure the logic probe isn't flashing green with the engine running? Both sides red mean it isnt getting a pulse.
Is that the old bad ecm or a new good one?
Are you sure the logic probe isn't flashing green with the engine running? Both sides red mean it isnt getting a pulse.
Is that the old bad ecm or a new good one?
Last edited by 64Scout; Jan 6, 2022 at 08:22 AM.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
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From: near the thumb in the mitten
Logic probe is the wrong tool. It will be triggered very low voltage. You need a DVOM, noid light, and factory service manual. Poor connections and /or improper wiring will kill multiple ECMs. Poor or loose grounds a good place to start. Injectors are fused and powered with key on.
Are or were there any aftermarket gizmos installed altering original wiring? Under dash or hood.
Are or were there any aftermarket gizmos installed altering original wiring? Under dash or hood.
Thread Starter
Intermediate
Joined: Jan 2022
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I pulled every fuse
Still green light at pulse wire
put back in
pulled all inline wires at junction box behind battery
still green light present
put back on
unhooked starter wires
green light still present
only way to stop both green lights is to disconnect battery
Still green light at pulse wire
put back in
pulled all inline wires at junction box behind battery
still green light present
put back on
unhooked starter wires
green light still present
only way to stop both green lights is to disconnect battery
Melting Slicks
Joined: Mar 2001
Posts: 2,150
Likes: 304
From: Timra, Sweden
Nothing is powering them when it is green. Did you read the instructions for the test light?
Green indicates a conection to ground. Disconnect ECM and injector fuses and the green light probably goes away, or if you disconnect all injectors on that side.
With ECM dissconnected and measuring on the ECM side of one injector connetion the coil in the other injectors will create a path to the fuse and then to any other fuse on the same power feed. If anything else on that feed has a small connection to ground the green light will be there.
Green indicates a conection to ground. Disconnect ECM and injector fuses and the green light probably goes away, or if you disconnect all injectors on that side.
With ECM dissconnected and measuring on the ECM side of one injector connetion the coil in the other injectors will create a path to the fuse and then to any other fuse on the same power feed. If anything else on that feed has a small connection to ground the green light will be there.