'91 accord low rpms

[negativecreep934]

Car idles around 500 rpms with a slight vibration that increases if rpms decrease. Thinking that an idle adjustment is needed. Opinion? If you agree with my thought, where is the idle screw located?

[ProMan]

I have the same issue too. Especially when put in gear or have AC on, the RPM sometimes drops to 250 and the engine chatters pretty bad. Don't have a chance to dig into it. But as far as I know, it's either the IAC valve, idle adjusting screw, or wiring (signal ECM to open IAC when in gear or AC on).

[wiseguy01]

dont mess with the idle screw if need be the screw is on top of the throttle body right below a vacuum line or two u have to move the line to see it but i would check other options first before u counteract the low idle with adjusting idle because it will rev higher and you will open up a can of worms. far as u know ur tps can be the prob. try disconnecting tps with car on if idle improves then u know what ur prob is but warm the car up to operating temp first then check it and the tps is located on the throttle body too where ur gas cable connect ur tps is on opposite side and has a plug on it but when u disconnect it it might throw a mil aka check engine light. anyways if ur idle improves then u know what u have to replace

[wiseguy01]

just so u know i have a 93 accord so i know they have same motor and setup