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high rpm backfire.....

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Old 09-27-2006 | 04:27 AM
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Default high rpm backfire.....

Hey guy's, could use some help.
My car just developed a mild high rpm backfire.
At wot, just before the 1-2 shift [about 5900 rpm's] the car will backfire, not loud, but it is audible. It will stumble just a bit, and then once it hit's 2nd gear it pull's again w/o further problem's.
Have not done anything to the engine since my lid install last june, but I did not have this problem untill just yesterday.
I did mess around with the wiring a bit at the throttle body looking for the tps wire for my nitrous kit I am installing, but everything look's ok.
any idea's?
I have a 2001 Z-28
Old 09-27-2006 | 10:16 AM
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plugs?
Old 09-27-2006 | 10:57 AM
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5900 on the tach may be 6200 in reality. Has the weather cooled off enough it could be pulling harder and bumping the rev limiter?
Old 09-27-2006 | 01:42 PM
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The plugs should be fine.
I just turned over the 30000 mile mark.
I am wondering if it could be tapping the rev limiter.
The only thing is that I have read when you hit the limiter the tach needle bounce's all over the place and the engine fall's on it's face.
My car isn't doing that. It just sort of cough's, then take's off again.
I guess I'll have to take it to the shop and get a diagnostic.
Old 09-27-2006 | 02:02 PM
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The rev limiter idea is probably the most likely if you can feel it cut out. At high RPM, one misfire isn't going to feel like much. You can feel it, but its not significant.
Old 09-27-2006 | 02:05 PM
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So does this mean my tranny is starting to slip?
Old 09-27-2006 | 02:14 PM
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An A4 is always going to slip some, or the shifts will be violent and the gears won't have time to engage properly. So yes your tranny is slipping, but slipping more is a possibility. If you make more power, its going to slip a little bit more, and you may need to shift at a lower RPM so it has time to get the job done before it hits the limiter.
Old 09-28-2006 | 11:13 PM
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Well, you guy's are going to laugh.
Checked my tranny fluid, [should have done that first], and I was a full quart down.
Seem's to be alright now, just hope I didn't do too much premture wear driving it when I was low.
Thank's guy's for your help.




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