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Aright this is what i got, i have 1 and 4 deadi have replaced the coilpack for them and it still persist. also i have have testedic controller and has failed for the required voltage. Now i am led to beleive that computer is the problem, i have no check engine light and it dose not cycle any codes. Has any one ever seen a car run on two with a dead computer or maybe solved a similiar scenario


thanks,


Steve</BLOCKQUOTE></BLOCKQUOTE>

 

My car (1997 Saturn SL) ran on two cylinders, not well, but it idled with only two spark plugs firing. I assume that you mean that when you remove the spark plug boot from cylinder 1&amp;4, there is no spark jumping to the motor or spark plug. As you are standing in front of the car, the right coil pack fires cylinders 2&amp;3 and the left coil pack fires cylinders 1&amp;4. These coil packs sit on the ICM (ignition control module), that part plastic part metal plate. It reminds me of a hot plate in appearance. You can actually switch the coil packs around. Left to right and right to left. If the same cylinders (1&amp;4) do not have spark going to the spark plugs, then both coil packs are good. The problem lies with the ICM, only one side is functioning properly.You can use an ohm meter to check the resistance going through each side by removing the coil packs and probing the metal contacts that plug into the coil packs. Both sides should be the same. Mine were not, so I knew the ICM was bad on the one side.A new ICM with coil packs is approx. $250. I went to a salvage yard and paid $42 for a used one.
Make sure you clean the contact surfaces on the motor where the ICM mounts with sand paper and then apply dielectric grease. Also wire brush the four bolts that hold the ICM and coil packs to the motor. The ICM gets its ground through these matting surfaces. Corrosion will cause the ICM to malfunction if it loses it's ground. Let me know if this helps.[img]smileys/smiley1.gif[/img]