Mechanics

WHY WONT THE CAR START ON A NEW COIL BUT IT WILL THE OLD ONE? AND IT MISSES.

2001 Saturn L100 • 95,000 miles

Recently the car would not start and I diagnosed a bad ignition module. I replaced the module and the car started and ran fine. A couple days later it developed a light miss. It randomly but very regularly coughs, sometimes its bad, sometimes its not too bad. I did a basic tune up with plugs and a fuel filter. No change. I finally decided my coil pack was faulty, so I got one, it will not start at all on any new coil. I got one from the parts store and from the dealer. It will start back up on the original one, but still misses. I dont know what to do. Any thoughts on why no coil will work with it? Thanks.
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Jrscars
November 20, 2011.




I replaced the ignition module with a new one, the miss persists, also I notice when the lights are on everything flickers a little, but the battery is charging at 13.8. Do I have a possible short in the ignition system? What a nightmare.

Tiny
Jrscars
Dec 2, 2011.
It sounds more like either the alternator going out or a ground issue. Check the grounds for the coil packs as well. Check the condition of all the wires.

Rivermikerat
Dec 2, 2011.
Got a coil pack and module together at a salvage yard, it came off of the same car. It works, but only with the module that came with it. The module that was on the car will not work with the one I got from the salvage yard. It does appear to have fixed the miss. So apparently, coils and modules have to be sold in sets.

Tiny
Jrscars
Dec 5, 2011.
Thats why I always have a coil assembly with module to swap out. But I have never ran into the problem you had at saturn the coil came as a assembly less themodule.I would then swap over the module from the car and it worked great. But those were all factory parts. Maybe some of the aftermarket coil or modules have a compatiabilty issue?Glad to hear you got it figured out though.
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Saturntech9
Dec 5, 2011.

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