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Idle Problem - Yeah.. Yeah.. Same Common Problem... Or is it?

2871 Views 26 Replies 12 Participants Last post by  88351stang
I would reset the base idle using the usual methods. When coming to a stop, i depress the clutch and the RPM's jump to around 1800rpm. At a full stop, the RPM's will drop where I want it- 850rpms but not after hanging at high RPM. The Idle Bypass Valve is clean; Throttle Body is clean; the air-idle spacer thing has no effect. TPS is at 0.98volts and a recent dynotune says that all settings is where it should be.

I've done everything yet nothing seems to work.

I also cleaned the MAF element. One of the elements has a darker color than the other. I use almost a full can of throttle body cleaner on the darker color element but no change. I assume that it's clean despite the darker color.

The idle is irratic and it sounds as if it will die.. almost spurring. At 850rpms the idle should almost be rock solid but this is not the case.

I am suspicious my of alternator, a Power Master (the Black one). I think it puts out 130A. When i turn on my dual electric fan, the overall power drops slightly. Is there a way to test it?

At this point i'm believe that the problem has to be a bad part
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I replaced IAC and I put in a brand new TPS, during the weekend. I don't think it helped.

When depressing the clutch to shift gears, the RPM's don't drop. They either stay at the current level or increase (surge). Then coming to a stop, I step on the clutch and the engine revs up instead of dropping to idle. I screw in the idle stop screw just up until the screw touches the blade. I then give it one full turn. I then set the TPS to 0.98 volts and start the car. Still nothing. Idle is still erratic. Yes... i've cleanerd


Can an exhaust leak at the header cause this strange behavior with the idle?
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