fatpride111

94 civic w/ b18c5 swap, even with the ac off, when coming to a stop light, or I throw the car in neutral and let the rpm's drop back to idle, it always goes down to about 200-ish rpm, battery light comes on, sometimes oil light comes on (pretty much everything with the key in the "ON" Position). once it hits about 200-300, and then it will slowly go back to about 750-800rpm within about 15 seconds.

When I turn the AC on, the rpms pretty much drop to 0 as soon as the compressor engages. It usually idles at 200, but will slowly drop and turn off.

I tried adjusting the idle screw on the TB but last owner f*cked it up, and its stuck, and all chewed up. I managed to get about half a turn on it, but it didnt help. Also took some advice from another forum and cleaned out the IACV, and TB, and it did help bring up the revs by about 100rpm, but still having the same problem.

90sedan

Does the car only want to stall out when there is a lot of load on it? Say at night, when you have the headlights/rear defroster/ac etc. on? Then it's possible there could be too much electrical load for the battery. How old is the battery? OEM size/cca? Try swapping it out for a known good one and see if that helps.

If the car has trouble idling after coming to a stop without any electrical loads on, and it wants to stall out, i would check for a vacuum leak.

fatpride111

BAttery is about 2-3 weeks old. Even during the day when I come to a stop light, and I have just the radio on, It will usually drop to about 300rpm, and slowly come back up to normal.

It drives the same at night with the lights on. I will check for a vacuum leak.

Someone mentioned something about a sensor or something that tells the ECU when there is load on the engine to pick up the rpm's... any idea what they were talking about?

BrandonR

My Z6 does that on occasion. I'll be in neutral rolling to a stop light and it will be idling at ~500 but as soon as I stop it idles back up to ~800. Only in really cold temps though. I say since your idle screw is chewed up, your PO tried to just use that to bandaid a bad/going bad IAC. I get a new one.

90sedan

There is an ELD (electronic load detection) unit, that helps regulate the current from the alternator to other electrical systems that require less/different amounts of current. It's normally located in the underhood fuse box, i'm not sure if if can be replaced without replacing the whole fusebox on your car, but it usually can. It's possible that the eld has failed, which could explain the difficulty idling. Try swapping it out.