I've got a '91 318is, today I got in it to run up to the store, and it started + ran fine for the first mile or so, then it began to run rough, and was really down on power. I continued to the store, but had to feather the throttle to get the car to accellerate, and it continued to run poorly, down on power.
I popped the hood and checked the plug wires to make sure they were all properly seated, and they were OK. I could not find anything loose, no bad vacuum leaks. I noticed some smoke coming from under the car, and saw the side of the cat was glowing slightly orange!! I'm guessing either the cat failed, or one cylinder is not getting spark, so the unburnt fuel is getting caught in the cat- making it get REALLY hot (this may be the cause of the cat failure).
Anyone have the test specs for these coils?? Anyone have any ideas on how to figure out if it's the cat that failed on it's own, or something that caused the cat to fail or ?????
I've got a couple of spare (used) coils to use for troubleshooting, but the next step is to pull the plugs + see what they look like (I'm waiting for the car to cool down now...)
Bret.
I popped the hood and checked the plug wires to make sure they were all properly seated, and they were OK. I could not find anything loose, no bad vacuum leaks. I noticed some smoke coming from under the car, and saw the side of the cat was glowing slightly orange!! I'm guessing either the cat failed, or one cylinder is not getting spark, so the unburnt fuel is getting caught in the cat- making it get REALLY hot (this may be the cause of the cat failure).
Anyone have the test specs for these coils?? Anyone have any ideas on how to figure out if it's the cat that failed on it's own, or something that caused the cat to fail or ?????
I've got a couple of spare (used) coils to use for troubleshooting, but the next step is to pull the plugs + see what they look like (I'm waiting for the car to cool down now...)
Bret.
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