86 fuel injector problem
Race Director
Joined: Oct 2008
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From: Lansing MI
I guess if I were you, I would put it all together and use a test light connected to battery positive, that way you can properly test for ground with at least some amperage. Disconnect one of the effected injector connectors, and while its in the failed state, probe the ground side of the connector, if the light illuminates, then the wire must be grounded. It could be because the harness is shorted, or because the ecm is shorted internally. Disconnect the ecm and repeat, if the short is gone then consider replacing the ecm, if the short is still present then the harness must be rubbed through somewhere or otherwise shorted to ground.
Burning Brakes
Joined: Nov 2016
Posts: 761
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From: Buchanan GA
That would be my vote. Not sure if there is a way to troubleshoot the ECM without replacing it but that's the only thing I can see causing this issue if the wiring is good.
Race Director
Joined: Oct 2008
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From: Lansing MI
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Heel & Toe
Joined: Mar 2018
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yep got Ray sending me one next week, I’ll keep all fingers crossed when trying that one out
thanks for your help guys
- 1986 Original Owner -
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While you’re waiting for the ECM, disconnect all the injectors and ohm check each one. An injector with very low resistance could have caused the injector driver in your ECM to fail. If that’s the case, the new ECM would work for a while, then it could fail too. So a failed ECM could be the result of bad injectors. A cold ohm test of the injectors only tells part of the story though. If all your injectors ohm check good, connect the ECM I’m sending. If the car then runs, let it warm up, shut it down and retest all the injectors again. If they are still good, smile, it was just a bad ECM.
Of course you’ll want to change the oil to get rid of that fuel and you might also want to pull the plugs in case any fuel is still in the cylinders.
I’ll get the ECM in the post on Tuesday.
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Heel & Toe
Joined: Mar 2018
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Yep oil changed and plugs are out, all the injectors are new AC Delco ones and haven’t even been run as yet, can’t start the car as it floods straight away.
Was testing it last night and with the ecm connected it’s grounding all 8 injectors at the same time, with ecm unplugged none are grounded, so my only thinking is the ecm has failed.
Was testing it last night and with the ecm connected it’s grounding all 8 injectors at the same time, with ecm unplugged none are grounded, so my only thinking is the ecm has failed.
Team Owner
Joined: Jul 2004
Posts: 28,502
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From: Hartford WI
Yep oil changed and plugs are out, all the injectors are new AC Delco ones and haven’t even been run as yet, can’t start the car as it floods straight away.
Was testing it last night and with the ecm connected it’s grounding all 8 injectors at the same time, with ecm unplugged none are grounded, so my only thinking is the ecm has failed.
Was testing it last night and with the ecm connected it’s grounding all 8 injectors at the same time, with ecm unplugged none are grounded, so my only thinking is the ecm has failed.
https://cimg8.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/439x307/80-fuel_20_inj_20_types_b286651dd51cb8e492f 4d467992d232158ba8956.jpg
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- 1986 Original Owner -
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Yep oil changed and plugs are out, all the injectors are new AC Delco ones and haven’t even been run as yet, can’t start the car as it floods straight away.
Was testing it last night and with the ecm connected it’s grounding all 8 injectors at the same time, with ecm unplugged none are grounded, so my only thinking is the ecm has failed.
Was testing it last night and with the ecm connected it’s grounding all 8 injectors at the same time, with ecm unplugged none are grounded, so my only thinking is the ecm has failed.
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Heel & Toe
Joined: Mar 2018
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SHE RUNS !!!!!!
Thanks to all that that helped with this, turned out to be the ecm grounding all the fuel injectors at the same time, fitted a new ecm ( supplied by Ray ) and she fired right up better than it ever did before !!
Thanks to all that that helped with this, turned out to be the ecm grounding all the fuel injectors at the same time, fitted a new ecm ( supplied by Ray ) and she fired right up better than it ever did before !!