i have a 91crx HF with a d16z6 in it
ive always had a small idle surge
recently my alternator went out
i replaced it and now the idle surge has gotten worse
i checked vacumm lines i found that the FPR was unplugged
i plugged it back in and it settled down a bit
but its still worse than it was before i replaced the alternator


any help is much appreciated. thank you

 

Surging idle is usually associated with a vacuum leak or air in the cooling system. I would start by doublechecking all your vacuum connections and rebleeding your cooling system and then go from there.

 

If the idle goes up and down it could possibly be the idle control valve located behind the intake manifold. This has a black housing solenoid in it an utilizes one plug with two water inlets. Disconnect, clean with carb cleaner and blow out, and reinstall. If this doesnt work, then replace. If the idle just stays high and you cant regulate by distributor or idle control on throttle body, then check your throttle body for the two water lines right under it. This utilizes a pressure system and if it malfucntions, then it needs to be replace. Its right under your throttle body and its held on by 3 10mm bolts.

 

thank you for the advice ill check that stuff out.