Replacing the idle air control valve to solve erratic idle speed. IAC Valve.
The Renix Engine fuel injection controller adjusts the idle speed by opening and closing a valve that bypasses the throttle plate. Often the Renix engines will have a high idle speed due to the Idle Air Control Valve leaking air past the plunger.
Mine has had an intermittent high idle speed since I have owned it. Most of the time it is not a problem; but sometimes when rock crawling in a delicate spot, a high idle speed can be annoying or even dangerous. Tapping the throttle body usually settles it down.
I finally got around to replacing the valve. It is held to the throttle body with two Torx screws. A Torx driver may be easier to use than a bit on a ratchet for the lower screw.
Be sure to remove the old O ring when cleaning. Use some throttle body cleaner to clean the seat inside the throttle body.
Install the new valve and O ring. I reused the old screws instead of the new ones in the kit.
The idle speed came right into spec on the first start up for me. I thought it might take the computer a bit to learn the new valve, but that was not the case.
I tried several starts and the engine would come right back to the proper idle speed every time. Hopefully I have solved this intermittent but annoying problem.
I got the Idle Air Control Valve IACV for Jeep Vehicles 17119295 from Amazon.