Getting Misfires Help
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From: Huntersville, NC near Charlotte
Getting Misfires Help My engine is missing badly so I got it scanned and it reads misfire in # 7 so we change the plug and wire and reset it and scan it again. It reads the same thing. What could make my car's engine hesitate and skip like this? It happens mostly between 2 to 3 thousand rpms and it surges some at idle.
Launching!
Joined: Nov 2001
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From: Burlington ON Canada
Re: Getting Misfires Help That problem sounds very familiar. Between 2400-2600 rpms under light load, tons of misfires on Cylinder 7. None on any other cylinders.
I changed plugs, wires, injectors, and coil packs, and the problem persisted. I pulled the push rods, and put on new heads with new springs. Still the same problem.
I'm thinking its a short somwhere in the wiring harness, in the meantime, I don't cruise at those rpms.
I changed plugs, wires, injectors, and coil packs, and the problem persisted. I pulled the push rods, and put on new heads with new springs. Still the same problem.
I'm thinking its a short somwhere in the wiring harness, in the meantime, I don't cruise at those rpms.
Re: Getting Misfires Help Same symptoms here, replaced plugs/wires/coil, looking at O2s right now as the culprit. Only SES code so far was P0300 random misfire, but occured on #7. If I monitor ATap I can see 2 misfires on #7 register when I hear the miss in the exhaust. Only under light load right around the same RPM range you mention. WOT doesn't seem to be affected.
I haven't checked pushrods or rockers yet, but I'm a stock valvetrain A4 with no recent trips to the rev limiter...
TTT for us. Maybe someone will "stumble" onto something. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Happy driving,
Bad30th
I haven't checked pushrods or rockers yet, but I'm a stock valvetrain A4 with no recent trips to the rev limiter...
TTT for us. Maybe someone will "stumble" onto something. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Happy driving,
Bad30th
Staging Lane
Joined: Jan 2002
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From: Cuyahoga Falls OH
Re: Getting Misfires Help I had the same problem with number 2. It would set the code between 2-3K rpms. My #2 plug was black compared to the others, it turned out to be a broken valvespring.
Good luck!
Good luck!
Re: Getting Misfires Help Fastmatt98,
Is your car a M6 or A4?
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Reboot:
<strong>Could be an injector
Broken valve spring
Bent pushrod (most likely if you ever hit the rev limiter)</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Hitting the stock rev limit isn't an issue, that's why it's there to limit the rev's before damage occurs.
Missing a a shift and over-reving the engine will bend a push rod in a heart beat.
Is your car a M6 or A4?
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Reboot:
<strong>Could be an injector
Broken valve spring
Bent pushrod (most likely if you ever hit the rev limiter)</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Hitting the stock rev limit isn't an issue, that's why it's there to limit the rev's before damage occurs.
Missing a a shift and over-reving the engine will bend a push rod in a heart beat.
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From: Huntersville, NC near Charlotte
Re: Getting Misfires Help I have a M6. I think it could be a pushrod but all my buds think its plugs or computer but I havent been to the limiter from what I remember, oh and don't forget it was 3 quarts low when I checked it the other day(changed the oil 2 1/2 months ago)I couldn't tell you where it went, no leaks at all. When it surges at idle some it makes a lower more hollow tone and slower idle. It lasts about 3 to 4 seconds then back to normal and of course it still has the skipping around the 2k to 3k mark. I just got a cam delievered and I'm dying to get it installed, gotta hate it when **** like this happeneds
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