Rough Idle and hesitation on 91 NSX - worst when cold

[huyduchoang]

My 91 NSX has a slightly rough idle, RPM is rock solid however so its not that bad.

Also there is some hesitation when bringing it up to 2000 rpms.

I am replacing the spark plugs (NGK 6) this weekend..... and testing the coils while I am at it and adding some Fuel Injector Cleaner. Anybody have similar problems or any suggestions on what else to check.

 

[Briank]

You could have a failing throttle position sensor, a bad temp. sensor, a vacuum leak or just a bad tank of gas. It's hard to guess without more info. From a cold start what kind of RPM do you see, what is the idle when warm? Do you have any mods?

 

[huyduchoang]

its not a bad tank of gas. if I remember correctly idle is around 1500-1700 when cold and warm idle is at 900

thanks in advance for your help.