Setting Base Idle

I can answer a couple of your Q's. The voltages I don't remember right off bat.. someone like HISSIN would recall.

To set base idle, unplug the IAC. If it stalls doing this, first turn the screw clockwise a couple turns so the thottle is open a tad bit more. The engine should be fully warmed up also, so no cold idle adjustments. Disconnect, then turn screw til idle sits steady at 750 rpm. Shut off engine, then plug IAC back in. Base is now set.

It probably would be a good idea to clear KAM. Otherrwise it will have stored codes from the IAC removal and previous adjustments may give an incorrect calibration. Remove battery cable for 2 minute. I sometimes had to leave it for 5 minutes just because there was residual components keeping the KAM afloat longer. Re-connect battery, start and let idle for about 10 minutes. Do NOT mess with the throttle or touch anything that may interferre with the learning process. After 10 minutes, take it out for a drive so it can better calibrate the TPS and set AF ratios. Just helps it run a little better in the long run.

I'm not sure about the TPS. It has a slot in the middle that the throttle plate turns by twisting a flat stem inside the TPS to rotate it. It retracts back to it's set position so I honestly don't know how they done it. I once bought a replacement TPS (which is the current one I have) , it has 3 screw hole positions on each side. I think you set it by removing the screws and re-inserting it in by either 15 degrees couterclockwise or 15 degrees clockwise. Its normally set in the center position, which is stock. Why do you need to adjust it?

There are several methods for setting the idle. I do it as MustangLX-5.0 noted however. Mods and the state of tune can dictate which methods work.

Do be sure the engine is fully hot and all accessories are turned off before you set the idle.


As said, don't sweat the TPS. If it's out of range, it will log a code. If you really wanna check it, just make sure it's in the ~0.60 - 1.20 V range (KOEO). If outside that at idle (or KOEO), it should generate a code.

For the KAM, just disconnect the battery and turn on the headlights for 30 seconds. That'll discharge the capacitors. Turn off lights off and reconnect the battery.

I would mark the adjusters and take notes of all changes you make. That way you can get it back to how it was if you need to. Sometimes people end up out in left field because they change the timing, idle setting, get or fix a vacuum leak, have a dirty IAC, etc etc. Logging all changes is a good idea.

Do you have a decent cold idle (at or over 1K RPM initially)? Does the idle kick up a little when you turn on the AC? If no to both, the IAC is likely not doing too hot. You could try to clean your old one (always assume if you clean it, it will crap out though. Sometimes they get worse after a cleaning).

I use WD-40 and then electrical contact cleaner to clean them. They can get pretty coked up inside. Let it marinate with the WD or cleaner for awhile, rinse and repeat. A cotton swab can help remove sludge.

Good luck.

subscribed Ill give that a try