Cylinder 4-5-6 misfire issue revisited. Insight still needed (not long)
03-11-2006, 06:21 AM
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Cylinder 4-5-6 misfire issue revisited. Insight still needed (not long)
After reading the original post (see link) you will see how I've already switched coil packs. Now I'm being told that I should move the cylinder 4 spark plug around to see if the misfires move to cylinders 1-2-3. But here's the question. The initial post about all of these issues came from my CEL coming on then going off just to come back on again. Here's what I was experiencing: CEL comes on, I drive ~40 miles and then it goes off for ~30 miles. After that it comes back on while warming up the car in the driveway, it stays on for another~50 miles then goes off to once again come back on 20 miles later.
So my question is that if this is a spark plug issue then why would my CEL come on and go off in the manner I described. Wouldn't misfires cause the CEL to stay on all the time? In my case it comes and goes. Grrr, any ideas before I start swapping plugs<ul><li><a href="https://forums.audiworld.com/s4/msgs/2288055.phtml">Original thread</a></li></ul>
So my question is that if this is a spark plug issue then why would my CEL come on and go off in the manner I described. Wouldn't misfires cause the CEL to stay on all the time? In my case it comes and goes. Grrr, any ideas before I start swapping plugs<ul><li><a href="https://forums.audiworld.com/s4/msgs/2288055.phtml">Original thread</a></li></ul>
03-11-2006, 06:47 AM
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the fact that it comes and goes makes me think it isnt a coilpack, or a plug. and knowing you let
your car idle for long periods of time reinforces my thyought that an 02 sensor could be bad. that or possibly, although i doubt, an egt sensor.
of course this would be alot easier if i knew what code you threw....and if you swapped the ing-amps on top of the airbox to see if those are messed up.
of course this would be alot easier if i knew what code you threw....and if you swapped the ing-amps on top of the airbox to see if those are messed up.
03-11-2006, 07:49 AM
#3
Did you try the ignition amps/stages? (those things on the airbox)
I have been f*cking with mine all week. There are two of them and apparently they each control a cylinder bank. One is 1-2-3 and the other is 4-5-6. That would seem to fit into your problem.
Of course, you may have already tried that.
Of course, you may have already tried that.
03-11-2006, 10:37 AM
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So considering the CEL coming and going; would would you definitly rule out the plugs?
And you're right sometimes I let the car warm up for up to 10 minutes this winter when it was really cold, simply because I don't like freezing my *** off. Can warming the car up for that long really screw the o2's?
03-11-2006, 10:42 AM
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Do not rule out the plugs IMO. *EDIT*
I could definitely see your car misfiring when idling for 10 min to warm up in winter.
sporadic* ;-)
*EDIT*
CEL comes on for misfires when ECU sees over X # of misfires in a given cycle AFAIK. In my case, CEL stayed on afer that. I assume this was because the problem repeated itself often enough to not clear the CEL However, I wouldn't be suprised to see it going away if the problem did not repeat itself for a certain extended period of time....and then returning once enough misfired registered in a given cycle. Idling in the cold weather for an extended period of time would probably exacerbate the problem, mkay.
sporadic* ;-)
*EDIT*
CEL comes on for misfires when ECU sees over X # of misfires in a given cycle AFAIK. In my case, CEL stayed on afer that. I assume this was because the problem repeated itself often enough to not clear the CEL However, I wouldn't be suprised to see it going away if the problem did not repeat itself for a certain extended period of time....and then returning once enough misfired registered in a given cycle. Idling in the cold weather for an extended period of time would probably exacerbate the problem, mkay.
03-11-2006, 10:49 AM
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So you're thinking that it's fouling the plugs by idling once or twice a week for 5-10 minutes?
How funny would it be that if my problem is derived by my "warming" up the car! I swear, how ironic would that be.
But really though, most of the time I warm up my car its in the neighborhood of 3-5 minutes and primarily its due to my not wanting to freeze for the first 5 minutes that I'm driving.
But really though, most of the time I warm up my car its in the neighborhood of 3-5 minutes and primarily its due to my not wanting to freeze for the first 5 minutes that I'm driving.
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