idling gone mad when a'cond compressor kick in.

[Hulktezza]

Hi guys, need your opinion here...currently rb20det is the heart of my ride, it was fun , smooth and suite me very well....until about 2 weeks ago, the engine stall when the a'cond compressor kick in, it wont immediately stall it took about 5 to 6 time (compressor kick in)...then it stall. the rpm when down from 900 to 300rpm n when up back to 500...but it took quite a while before it reach 500 to 600 after the compressor kick in.

I already clean the TB...nothing change, clean n replace the AACV...same result,

what should i do now....with out the a'cond the engine idle n run very smoothly.

Thanks in advance for your help.

[Skym]

That can happen when TPS is misadjusted or TPS is old (idle contact bends over time). Check that TPS is on idle contact and there is no TPS error code on ECU. Also you'll probably find out that loading engine up on a fairly steep hill and suddenly backing off throttle can make rpm needle drop below idle rpm (650rpm).

[Hulktezza]

thanks bro...i'll will check it out ...asap,...any result i will update it here.

will it help if i adjust the tps position from it current setting.?

[Hulktezza]

check and replaced the TPS but the problem is still there....the symptom started only when i switch on the air conditioning. .....guys help!!!

[Skym]

Ok, so that eliminates TPS as a cause.

I think there's something on aircon that when you turn aircon on, makes ECU raise rpm up to 1000rpm. If faulty it might make rpm drop. I think it's to do with aircon headunit itself. Would need to get hold of a wiring diagram for aircon to find out exactly where wiring is and correct any bad solders.

The other is a bearing on front of aircon pump itself (from what I can remember, when pulled aircon pump apart, you can pull cover off bearing and grease bearing). If aircon hasn't been serviced properly (oil and new gas), aircon pump can make a knocking sound when turned on (multiple little pistons inside that have balljoints on each end of the rods going to pistons that can lock due to lack of oil hence the knocking sound).

[Hulktezza]

thanks dude, i will look into it.....

[specialedition]

My cars having the same problem, well similar. I have idle bounce from 600-1000 when the a/c is on. The also doesnt react the same.

[Skym]

Or it could be lazy o2 sensor + ECU making idle bounce. Lean = revs rise, rich = revs drop. Also ECU adjust's ignition timing to match (idle stabilisation). Unplugging o2 sensor should stop that. MAF could be the other.

[Hulktezza]

but why it only happen with a/c on.....when it off everything back to normal.

[R33rr]

FYI , as im told and what i have read . On aac valve there is 2 valves , i believe the purple end / controls the cold idle . then the other one is for when the AC is turn on . Both of the valves can be taken apart and cleaned .
give that a try

[beacher1B0]

Also could be the FICD solenoid. It activates the AACV open to let air bypass the throttle body, which in turn cause a higher idle when AC is turned on. There is a trouble shoot in the R32 engine service manual.

Also could be the switch that activates the FICD solenoid. Not sure where or what that switch is. If u had a consult cable and a laptop, easy to rule that out along with many other problems down the road.