2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

No spark, only while cranking

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Old Oct 9, 2003 | 12:01 AM
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From: sugarland, tx
No spark, only while cranking

Got this car a while back in non running condition, The motor in it had been incorectly rebuilt and had rusted inside. I bought a usable core, rebuilt it, and installed it, now i'm having some ignition problems... The car started up and ran just fine probaly ten or more times but would not idle so i could not keep it running. Now the car will not spark while cranking, only when the key is in the on position (push starting). I tested this by taking all 4 plugs out of the motor, laying them on the intake with plug wires attached. crank motor and nothing happens. now leave the key in on postion and push car and sparks happen. Any ideas????????

Also i have many extra parts and have changed ECU, CAS, COILS, and the EGI relay
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Old Oct 9, 2003 | 08:00 AM
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From: sugarland, tx
I've searched and searched and cannot find any info on this problem

anyone?

this is an 86 base n/a

after checking voltages last night, i'm seeing that the ECU is not pulsing the trigger wires for the coils while the engine is cranking, but if you aren't cranking and the motor is spinning it will

Last edited by SilverRotary; Oct 9, 2003 at 08:20 AM.
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Old Oct 9, 2003 | 08:45 AM
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From: Forest, Ontario, Canada
Sounds like a grounding problem to me, though it could be the ignition switch/IGI circuit.
While you are cranking, very large currents flow through the ground connections. A high resistance at the grounds, causes a large volt drop to the ECU. Enough, I would suspect, to stop the processor from running.
You could test for this by putting a DVM from, say, your 60A main fuse and actual Chassis, a bolt or something, and see what the voltage is while cranking (or at the ECU if you have the carpet/cover plate off).
If that test is inconclusive, measure the power supply to the ECU at the ECU terminal 3J, while cranking.
Let us know what you find,
Dave
Have you have checked all the fuses?
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Old Oct 9, 2003 | 09:18 AM
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yes i've checked all fuses Also i found some posts from the previous owner the had the car and the same problem that i inherited. http://www.teamfc3s.org/forum/showth...&threadid=6780 http://www.teamfc3s.org/forum/showth...&threadid=7637

i'll check the current drain tonight when i get home

Last edited by SilverRotary; Oct 9, 2003 at 09:46 AM.
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Old Oct 9, 2003 | 10:58 AM
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any other thought besides ecu ground? i wanna make the most of my time this evening as i need to get this car running
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