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1996 Corvette changed coil and controller. now won't start

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1996 Corvette changed coil and controller. now won't start

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Old 05-16-2018, 09:23 PM
  #21  
MatthewMiller
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Originally Posted by Southern Boy View Post
Thanks to an idea here, I was able to put a spark tester on where I could see it while cranking over the engine. No spark! what could I have done by changing the coil and ICM? The original ICM and coil are back on the car so it isn't a matter of defective new parts.
Time to start tracing the ignition circuit backwards. Do you have spark at the output of the coil (test the same way)? If not, are you getting signal to the coil from the ICM? If so, is the ICM getting its signal?

Here is a useful diagnostic procedure for some of this stuff: http://easyautodiagnostics.com/gm/4....test-the-icm-1.

Last edited by MatthewMiller; 05-16-2018 at 09:31 PM.
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Old 05-16-2018, 10:25 PM
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Just another approach to checking spark that I've used. It works for the coil wire as well.
I use an inductive timing light like a noid light. Just clamp to any wire and hold it while starting the car. It will flash if there is spark.

Coil wire will flash so fast it will look solid but it still tells you the light is seeing spark.
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Old 05-16-2018, 10:52 PM
  #23  
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Originally Posted by FAUEE View Post
You need to follow shbox lt1 no start guide.

From memory, to get spark the icm needs a signal from the ecm to send the trigger to the coil. Then the coil woll fore, and send spark thru the opti. So I would check if you'e getting signal to the icm, and then from the icm to the coil.

It's an old car, you may have broken a wore during the install.
FAUEE, my thanks to you and to all the helpful members of this forum who responded to my request for help! It was exactly what you suggested - the wiring is old and I must of broken a wire when doing the install. After fixing, she instantly fired up and ran. I have decided to live with a uneven idle for now rather than going through this issue again. Thanks again to all!
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Old 05-16-2018, 11:59 PM
  #24  
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I'm very glad you solved the biggest issue! It's an easy problem to have on a car as old as ours.
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Old 05-17-2018, 08:46 PM
  #25  
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Ring out the wires you removed. You most likely have a break in the circuit!
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Old 05-17-2018, 11:05 PM
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Originally Posted by fake View Post
Ring out the wires you removed. You most likely have a break in the circuit!
Fake, forgive me, I'm just a farmer. What does ring out the wires mean?
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Old 05-17-2018, 11:09 PM
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Originally Posted by belairbrian View Post
Just another approach to checking spark that I've used. It works for the coil wire as well.
I use an inductive timing light like a noid light. Just clamp to any wire and hold it while starting the car. It will flash if there is spark.

Coil wire will flash so fast it will look solid but it still tells you the light is seeing spark.
belairbrian, that is a great idea and certainly helpful for someone like me having to crank over the engine by themselves while simultaneously checking for a spark. Thanks!
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