Author Topic: floating idle?  (Read 2429 times)

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redline

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floating idle?
« on: July 18, 2008, 03:17:14 AM »
I've been noticing a few symptoms on my car that seem strange lately and it's really worrying me seeing as how I'm passed my timing belt time.

 - floating idle: my engine usually sits at about 900 but lately it will float very slowly between 950 and 750. Never that big of a range at once, maybe between750 and 800 at a light, but still noticeable.
 - engine shake: some days my engine will shake the whole car.
 - loss of power: my engines seemed a little sluggish lately, it's hard to tell when you are slow already, but it just doesn't feel like it has much oomph.
 - momentary stutter: once or twice on the last few weeks as I am gassing it, always above 3k rpm it stutters for a milli second and then regains.
 - slight valve tick. I could be crazy, but I hear it. It gets worse as I rev it up.

Any ideas?
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92UrS4

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Re: floating idle?
« Reply #1 on: July 18, 2008, 11:44:07 AM »
When did you last change your plugs?

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Re: floating idle?
« Reply #1 on: July 18, 2008, 11:44:07 AM »

redline

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Re: floating idle?
« Reply #2 on: July 18, 2008, 04:08:06 PM »
I replaced the plugs a little over a month ago. I do have one bad wire that I've been meaning to replace though.
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92UrS4

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Re: floating idle?
« Reply #3 on: July 18, 2008, 04:13:47 PM »
If you have cracks or splits in the wires, a loose plug, or even a cracked or broken plug you could see this behavior.

redline

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Re: floating idle?
« Reply #4 on: July 18, 2008, 11:38:38 PM »
ok, thank you for the help Jay, I'll have to look into finding one more wire. Andrew (ar_design) scanned her today just in case and I got no codes, but he thought it might be my MAF or O2 sensor. Checkers wanted $190 per O2 sensor. ( I have 2 before the cats alone) Is there any way to test them?
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92UrS4

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Re: floating idle?
« Reply #5 on: July 19, 2008, 12:35:05 AM »
I would hit up AudiWorld on that, there will hopefully be more in depth info. DO a search for O2 sensor and the like. There should be numerous results.

Also, as for codes on our cars, we aren't as lucky as the newer car guys. We don't have as many ECUs.

90Carat

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Re: floating idle?
« Reply #6 on: July 19, 2008, 01:15:33 AM »
Maybe buy some MAF cleaner and give it a shot?  Also, clean you ISV and TB with some TB cleaner.  Bouncing idles can easily be caused by dirty ISV's.
have a 92 S4, and old Porsche, and some Japanese stuff sittin' in the garage.