Engine Idle Surge

[AxemanZZ]

I'd start with the free stuff like cleaning the throttle body and EGR valve with carb cleaner. You have to remove these parts to get all the gunk out but it's a really easy job to do as long as you remember where everything goes.

If you don't have a K&N air filter get one.

Then change your cap and rotor and do a regular tune-up. I've known a distributer cap to cause idle problems in the rain.

I also had a high idle problem just recently due to EGR dust build-up inside the throttle body causing the throttle plate to stick open a bit, but had nothing to do with rain.

Did you reset your computer after installing the new TPS? Disconnect the battery for at least a half hour to reset it if you haven't.

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90 Mustang LX 5.0
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