Idle Flux Capacitor Problem Options

[clownpRon]

Not really, of course. But my question is that on a cold start my engine idles high like usual. I can hear the SRI sucking like a vacuum. But when I turn the heater on the cars idle lowers massively, and the vacuum noise goes away. I don't recall it doing this at all during winter time, and it's still fairly nippy here. I'm thinking maybe it could be the alternator, but I'm not sure.

[Bitter]

there should be an axillary air bypass valve which opens when the AC compressor turns on, it supplies air in addition to the IAC under the throttle body. I think its at the passenger side of the intake manifold via a vacuum tube and the valve itself is located on the firewall, at least for a 7A-FE. My idle would dip a little but I don't remember it dropping that much. Check that that valve is working via a test light, it should turn on when the AC compressor is running and that there is vacuum at the valve with the engine at idle. Also clean the IAC under the throttle body, they tend to get full of gunk and crud and don't flow as much air as they should and don't move as much or as fast as they should.

It can also be worth while to check the calibration of the TPS and adjust it (also the throttle minimum position) to account for minute wear in the throttle stop. It only takes a tiny bit of wear to make a noticeable difference, you HAVE to recalibrate the TPS if you adjust the throttle closed position screw!!

[Spider77]

there should be an axillary air bypass valve which opens when the AC compressor turns on, it supplies air in addition to the IAC under the throttle body. I think its at the passenger side of the intake manifold via a vacuum tube and the valve itself is located on the firewall, at least for a 7A-FE. My idle would dip a little but I don't remember it dropping that much. Check that that valve is working via a test light, it should turn on when the AC compressor is running and that there is vacuum at the valve with the engine at idle. Also clean the IAC under the throttle body, they tend to get full of gunk and crud and don't flow as much air as they should and don't move as much or as fast as they should.

It can also be worth while to check the calibration of the TPS and adjust it (also the throttle minimum position) to account for minute wear in the throttle stop. It only takes a tiny bit of wear to make a noticeable difference, you HAVE to recalibrate the TPS if you adjust the throttle closed position screw!!

There is a valve under there, its the A/C Bypass valve, and its a bit adjustable. I messed with it a long time ago, it never did me any good (could be shot for all I know). I had enough of the crazy shake with the A/C on and took the slack out of the cable that runs from pedal to TB. Slight adjustment, idle a tad higher, but with a/c on its all ok. But, since this involves the heater and not A/C.............