Idle issues

[primespark22]

I have a 1992 da9 with a 98 b20b swap,i was driving the car with ac and had no problems it idle at 1000,It was time for a tune up so i popped the hood thats when i notice the vaccum line from the fpr was diconnected.I went ahead and plug it in started the car and it idle like at 2 300 rpms close to stalling.I left the car on and disconnected the the line and it shot up to normal,so i plug it in andturned off the ac and it went back to normal anybody have a clue of what this could be?

[CaTcH22]

The IACV may not be able to control the idle with the A/C on. Also see if the air mixture screw is set right.

[primespark22]

how can i fix that,i the screw but nothing

[SLo_MKIII]

how can i fix that,i the screw but nothing

take the screw out and see if the rubber o ring is any good mine wasnt and it caused my idle to be slightly high about 1700 to be exact

[CaTcH22]

You tried turning the air mix in all the way and then back it out till it idles up? If it will not set, then the IACV is probably bad. You pull it off and try cleanin it, but most of the time you have to replace it.

[primespark22]

yeah i screwed it in all the way and it died down a little,then i screw it out and the same it will change with 100 rpms nothing big you wont notice it,ima try the iacv and see what happens,if that screw is messed up how can i replace it

[SLo_MKIII]

yeah i screwed it in all the way and it died down a little,then i screw it out and the same it will change with 100 rpms nothing big you wont notice it,ima try the iacv and see what happens,if that screw is messed up how can i replace it

junk yard

[scttydb411]

w/ the vac line pulled you're getting a larger vac leak and also richer mixture b/c the fpr is at atmospheric pressure (wot fuel pressure). when you plug the vac line to the fpr it'll lean it out at idle b/c it's dropping fuel pressure. also you're getting less air in w/o the vac leak.

what ecu do you have running it? you should be able to raise the idle screw to fix the idle, but if the iacv is blocked or not working you'll have the issue you are describing as well. what tb, gasket, and intake manifold are you running?

any cel?