It kicks up to around 21% when I turn the A/C on, which also kicks my Contour fans to high. So if I adjust open the throttle to lower the IAC when the A/C load is there my idle will be high when the A/C is off. This was one of the things I hated about the Carb. I'd have to set the idle at 1200 to maintain 900 with the A/C & fans on. The way that a mechanic will narrow it down is to use a mechanics stethoscope. You can get one pretty cheaply at an auto parts store. Put the metal end of the scope on a part of the engine and listen for noise. On the other hand, if your car is idling at 5000 rpm, it would also be making ALOT of noise. Disconnect the electrical connector from the IAC valve. Take out the screws or bolts holding the IAC valve to the mounting plate. Take the IAC valve out of the car carefully. Install the new IAC valve in the reverse order of removal, making sure that it is securely mounted in place. Shift the outboard engine into forward gear. Starting turning the idle adjustment screw on the carburetor to attain the specified idle rpm. Refer to the download repair manual for idle rpm specifications. Rev the outboard engine 2 or 3 times and then allow it to idle for 15 seconds. If the engine holds a steady and stable idle rpm then no other Here are answers to questions about the a/c system: (1) pressure readings are 260 on the high side 30 on low side. (2)compressor pulley is only slightly larger than OEM. (3) i have tried changing the idle settings etc. (rpm' s drop by about 500 when a/c is on at idle. Reply Quote. Compressor kicking in every few minutes instead of every 20 minutes or so (normal cooling cycle) will wear it down quicker. Constantly cooling down the indoor refrigerant lines increases the chances of further problems you might have as a consequence of running an AC that is short cycling in seconds or minutes. AC not doing its job. k0hWlx.

how to adjust ac idle up