Misfire diagnosed and cured
#1
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About 1 month, 600 miles ago, I installed new plugs (NGK TR55). Ever since the install, there has been a ticking from the drivers side, low rpms when engine is under load. Basically every take off. I thought it was AIR tube gaskets or AIR valve, changed all those, did no good. Also, the SES light would come on for short periods of time. Car ran fine, except for the #@$#@ ticking. Well, this morning my SES light comes on and stays on all day. I take the car to auto zone, it is dropping the "misfire cylinder #1" code. So I check the wire, it's on tight on plug and coil. I check spark from the wire, it is fine. I pull the #1 plug, immediately I see the gap is waaaaay too tight. I get my gapper and the plug is gapped at .025! I must have hit it when I installed it, because I know it was gapped at .050 when I inserted it into the spark plug socket. So I re gap the plug, install it. Start the car, 10 seconds later the SES light goes out, I take her for a test drive and NO TICKING! Yahoo! That ticking was pissing me off so badly! The car is very smooth now.
Well, thanks for listening. Just posting because maybe it will help someone else diagnose some day. I wish I would have checked the plug FIRST.
Well, thanks for listening. Just posting because maybe it will help someone else diagnose some day. I wish I would have checked the plug FIRST.
#3
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Thanks. I wouldn't have thought it would cause a misfire signal. Can someone explain this one for me. Is it because the distance between the electrodes isn't wide enough to generate a hot enough spark (energy)???? TIA.
joel
joel
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Hmmmm...you got me thinking. I have an annoying tick on my LS6 that is very noticable around 1800 rpm under light load. I've checked the rockers, push rods etc. All seems well in the valve train. I have had the plugs out and they appear OK but maybe one of them just isn't doing the job as well as it should. I notice that the left exhaust pipe seems to have more soot than the right. I also notice that the left LTFTs are running more positive than the right. I wonder if I should replace the plugs before taking it to a dealer?
Was the tick loud enough to make you think it could be a lifter? BTW, I'm not throwing any codes but it doesn't idle as smooth as it used to.
Was the tick loud enough to make you think it could be a lifter? BTW, I'm not throwing any codes but it doesn't idle as smooth as it used to.
Last edited by jub jub; 02-02-2004 at 10:02 PM.
#5
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Originally Posted by jub jub
Hmmmm...you got me thinking. I have an annoying tick on my LS6 that is very noticable around 1800 rpm under light load. I've checked the rockers, push rods etc. All seems well in the valve train. I have had the plugs out and they appear OK but maybe one of them just isn't doing the job as well as it should. I notice that the left exhaust pipe seems to have more soot than the right. I also notice that the left LTFTs are running more positive than the right. I wonder if I should replace the plugs before taking it to a dealer?
Was the tick loud enough to make you think it could be a lifter? BTW, I'm not throwing any codes but it doesn't idle as smooth as it used to.
Was the tick loud enough to make you think it could be a lifter? BTW, I'm not throwing any codes but it doesn't idle as smooth as it used to.
Yes, it was loud enough to make me think it was a lifter, but I ruled that out because the ticking was faint to non existent when the car was parked and at idle, and almost non existent even when revving parked in nuetral. It was also not as bad when the car was VERY cold. But every time taking off from a stop sign or any stop, that is when it REALLY ticked. Especially when warmed up good. Also on 2 and third gear shifts, low RPM. It sounds like you may have the same problem, mine did not throw the code very often, and it only stayed on once. The only thing stored was misfire cylinder 1 as well. You will be so much happier once you solve that darn tick.
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Originally Posted by 98Z-6Speed
Yes, it was loud enough to make me think it was a lifter, but I ruled that out because the ticking was faint to non existent when the car was parked and at idle, and almost non existent even when revving parked in nuetral. It was also not as bad when the car was VERY cold. But every time taking off from a stop sign or any stop, that is when it REALLY ticked. Especially when warmed up good. Also on 2 and third gear shifts, low RPM. It sounds like you may have the same problem, mine did not throw the code very often, and it only stayed on once. The only thing stored was misfire cylinder 1 as well. You will be so much happier once you solve that darn tick.
I just bought a new set of the TR55s. If this fixes my tick I'll buy you a beer
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Well I just finished installing the plugs and it didn't help.
So I went to the dealer and told him I want them to look at the car. They say they won't touch it until the AVM listens to it. They told me the AVM was going to be here yesterday when in fact he was here Monday. The bastards lie to me so I can't see the AVM. I'm on the phone now with GM customer service talking to a guy who can barely speak english. I'm so pissed off right now. How in the hell does GM manage to keep customers when they treat them like this.
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