Ignition Issue
Ignition Issue I have started having issues with the ignition on my car. It started idling rough and fluctuating more than normal at idle. It then started hesitating upon acceleration. It got worse as I drove it home. However as long as the rpm was above about 2k, it seemed fine. I checked the wires (and the plugs are new). I drove it again tonight after sitting 24 hours and at first it was fine, but as soon as it started heating up, it started missing again. And it got progressively worse as it warmed up. I had the coil tested and it seems OK. I am thinking it could either be the Ignition Control Module or the OPTI. Both are original (as well as the cap and rotor) and have 115k miles. Does it sound like one or the other? Anybody have any different ideas? Thanks in advance.
well I mean when you say it is fine above 2k that doesn't really make sense if it was ignition I don't think. Usually ignition problems become more apparent at high rpm, not less.
When I said fine, I meant that it evened out a little and still ran. But if you give it gas to accelerate, it does miss a little bit. I am going to put the computer on it and check the O2 output but I just have the feeling it is an ignition issue but I don't know for sure and that is why I asked, so I appreciate the input.
When I said fine, I meant that it evened out a little and still ran. But if you give it gas to accelerate, it does miss a little bit. I am going to put the computer on it and check the O2 output but I just have the feeling it is an ignition issue but I don't know for sure and that is why I asked, so I appreciate the input.
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OK I have an update. I had the coil checked and it appears to be in spec with the resistance numbers. I purchased and tried a new ICM and it made no difference. I also ran the scanner and both O2s seemed normal. I ran the car for 10 minutes and I got an average of .509 volts left bank and .530 volts right bank (and both were replaced 1600 miles ago w/ AC Delcos from dealer). There are no check engine lights on but it acts like it isn't getting enough spark under light to moderate throttle. However under WOT, it didn't seem to be missing any although it didn't feel as strong as normal. Does this sound like an OPTI going bad or something else?
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Well it isn't knock retard, I checked that and the car is tuned really well. And as far as the O2s, they both had a wide range of movement from the bottom of the scale to the top.
I didn't check to see if it was in open or closed loop mode but it does seem to run normal when it is cold and starts acting this way as it warms up. But it starts mildly and gets worse the longer you drive, not just like an on or off thing.
I didn't check to see if it was in open or closed loop mode but it does seem to run normal when it is cold and starts acting this way as it warms up. But it starts mildly and gets worse the longer you drive, not just like an on or off thing.
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Joined: Oct 2006
Posts: 267
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From: Las Cruces, NM
i know you said you didnt have any codes. But mine is running like **** and i have a bad maf. im getting a new one tomorow. I dont think this will be your problem but it is worth haveing check again.
Mine did the same thing as you stated
when I first bought my car I washed the engine not knowing about the opti
the next day it was idling rough and fluctuating it ran bad but once you started driving it was ok
I replaced my opti it had 152,000 and it needed to be replaced it ran great.
when I first bought my car I washed the engine not knowing about the opti
the next day it was idling rough and fluctuating it ran bad but once you started driving it was ok
I replaced my opti it had 152,000 and it needed to be replaced it ran great.
I have decided to replace the opti and see if that is the problem. At 115k, it needed a new cap and rotor anyway so hopefully this will fix it. I also ordered an electric water pump that I am going to install at the same time. And if that doesn't work, I am going to stab myself with a spoon, run the car off a cliff (in Florida) and buy an LS1.
UPDATE 3: I replaced the OPTI with an AC Delco unit and decided to replace the wires as well because one wasn't staying connected to the cap. I also installed a Meziere EWP. The OPTI seems to have fixed the problem. Thanks for the help guys.
This Happen Too Me Twice Hard To Start Runs Rough, First Thing I Would Check Is The Ignition Switch Mounted On Top Of The Steering Col. You Have To Drop It But Its Really Easy to Do. Im Glad You Figured Yours Out, If Thats Anybody Elses Problem Try The Ignition Switch. And For Thoses Guys Who's Cars Just Turn Over Without Starting Ignition Controle Module
Last edited by djjab57; Mar 4, 2008 at 11:14 AM.
