DiscoStudd Posted July 23, 2004 Report Share Posted July 23, 2004 Alright, here's the deal: Wife's 96 Lumina, 3100, approx 144k on the odometer. About a week ago, after starting the car, it immediately begins misfiring. The MIL starts flashing. Rev the engine a bit, still misfiring. I take it to a friend who works at a shop and he scans it. Says cylinders 1 and 4 have a random misfire. I have an extra set of coil packs at home so I brought in a pack to swap out. Still misfiring. He does an amperage test on the plug wires (plugs and wires are 2 months old) and it reveals that there's less current being pulled on 1 & 4, so he checks the injectors. Both injectors weren't working. I have him replace the 2 bad injectors and clear the codes out of the PCM. Car runs beautifully after this for about 3 days. Then 2 days ago, same shit happens. Car's misfiring like it was before and the MIL is flashing. Took it back to my friend and he scans the PCM and it indicates the injector on Cyl. 4 had an intermittent problem. He cleared out the codes and told me to run some Seafoam in the tank and we'll take it from there. Well the car ran great for a day until this morning. I drove it around the block and it was misfiring again. I shut the motor off and when I restarted it it ran fine. I'm taking it in to have the injectors and intake power cleaned on Monday, but I'm kinda thinking the Ignition Module could also be at fault here. I didn't smell any raw gas when it was misfiring, but if cleaning the injectors out doesn't help, then I don't know what else to replace besides the ICM. I replaced the fuel pump and filter last year, so I'm positive that's not an issue here. Anyone have any suggestions? I would appreciate any help you could give me. Thanks! Quote Link to comment Share on other sites More sharing options...
Canada Posted July 23, 2004 Report Share Posted July 23, 2004 What are the exact codes being popped? Its a '96 so its OBD-II. PO300 is random misfire.....PO301 is #1, PO302 is #2, and so.....ANY others? #1 and #4 are both the same coil pack....I would of started there as well. If you think its the fuel pump.....put a gauge on it......should show over 35 psi, not drop during applied throttle, and should hold pressure for awhile.....my guess is that it will have all of those. Ignition modules usually show up as no spark at all.......not just some intermitent miss. If all else fails, I'm guessing its some type of failure in the harness giving you hell........good luck.........has any work been done to the car before the problem starter? What type of plugs are in it? Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted July 23, 2004 Author Report Share Posted July 23, 2004 What are the exact codes being popped? Its a '96 so its OBD-II. PO300 is random misfire.....PO301 is #1, PO302 is #2, and so.....ANY others? I'll have to ask my friend what exactly he pulled. He just said "Random Cylinder Misfire" the first time and the last time it was "Cylinder 4 Misfire." If all else fails, I'm guessing its some type of failure in the harness giving you hell........good luck.........has any work been done to the car before the problem starter? What type of plugs are in it? I haven't had any major work done to the motor at all since we've owned it (since Feb 03.) All I've done was change the plugs and wires a couple of months ago. I have NGK Platinum spark plugs in it right now. They look exactly like the original AC Platinums (not Rapidfires) that were in the car previously. Thanks for your input, Canada. I'll be sure to hunt down an injector harness this weekend and give that a try. I'm sure it wouldn't hurt to try it out. Quote Link to comment Share on other sites More sharing options...
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