LT1/LT4 Tech 1993-1997

engine cranks but no spark

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Old Feb 18, 2012 | 06:45 PM
  #1  
BM-Z28KING12's Avatar
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Default engine cranks but no spark

Hey guys I've been doing some work on my 94 z28 its been sitting a while when I got the car it was running then the water pump and distributor were done on it along with new plugs and a new coil.. does anyone know why I wouldn't be getting spark to it???
 
Old Feb 18, 2012 | 11:38 PM
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Apparently it is something happened due to the "improvements". Check all the wiring and connectors associated with opti, coil, and ignition module. Could also be one of the things you replaced or the ignition module are faulty.
 
Old Feb 19, 2012 | 07:40 AM
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Old Feb 19, 2012 | 08:31 AM
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thanks guys ill check this and see what i come up with
 
Old Feb 19, 2012 | 05:14 PM
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Just a heads up...Ive bought bad coils out of the box. Check it too. ICM is another goo one to check.
 
Old Feb 23, 2012 | 08:38 AM
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hey guys i was just doing some research and i remembered that i had my cam done in the car at the same time as the distributor... is it possible that it is the cam position that is off?? i tested the coil that that i got and its fine.. so the cam is just a thought
 
Old Feb 23, 2012 | 10:02 AM
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The cam being off wil not affect spark in the LT1, but may prevent the engine from starting. The PCM gets all its timing signals from the opti, so if it does not see the reference pulses it will not tell the ICM to fire the coil.
 
Old Feb 23, 2012 | 03:36 PM
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may have forgotten the coupler shaft for the opti or got the wrong cam for your opti.
 
Old Feb 23, 2012 | 10:36 PM
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That's what I was thinking that there could be spark but its just not firing right because of the cam im swapping out the opti again tomorrow so hopefully I can figure something out
 
Old Mar 1, 2012 | 11:26 AM
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I have this problem too, only mine ran fine yesterday I shut it off and it didnt start this morning. The previous owner replaced everything on the ignition system except the ICM. I looked at shoebox's test for the opti and I am assuming if there is the correct voltage to the ICM than the opti is good and the ICM is bad.
 
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