Low idle speed

[NSXsenior]

When I purchased my 91 it was December and the temperatures around 30 to 40 degrees and the idle speed was fine and engine smooth. Now that daytime temperatutres are 80 to 90 degrees the idle speed is low (approx 500 RPMs by the dash tach) and the engine a little rough (no stalling...yet) and sometime I get idle hunt.

Question 1: any ideas what would cause this?

Question 2: what is the procedure to turn up the idle? Other sport cars I have owned required jumpers in plug in connectors to cancel the engine management computer while a manual idle adjustment is made.

Any assistance would be appreciated.

 

[Briank]

The idle speed is controled by the ecu and is not adjustable. Normally a good cleaning of the throttle body should take care of the problem unless some one has messed with the factory settings of the air bypass or the throttle plate stop. A can of carb spray from the auto parts store is a good place to start.

 

[TomCat]

The idle speed is controled by the ecu and is not adjustable. Normally a good cleaning of the throttle body should take care of the problem unless some one has messed with the factory settings of the air bypass or the throttle plate stop. A can of carb spray from the auto parts store is a good place to start.

100% agree...especially if it "hunts" for idle.
Additionally, check/clean your air filter!!!