Hello all,

All and all my cars runs great. but, recently it started this strange idle problem. It seems that once the compressor kicks on the rpms drop form 12-1300 to 6-700. (according to the VAFC) Sometimes the car will begin to "buck" really bad until I turn the A/C off, than all is well again. I know what you're thinking, "Then just don't use the A/C." but, I live in GA and it gets hot as hell here in the summer. Having some cool air sometimes is rather important. The other time I noticed a significant drop in rpms is when the headlights come on. I have checked the grounds and they seem free of corrotion and tight. I recently replaced the MAF and I have cleaned the IAC less than 3k miles ago. Any one else experience this? Any help would be greatly appreciated.

Thanks, Keith

 

What kind of car is this?

 

im no expert but 1200-1300 seems a little high for normal idle anyway. is it a cold start when this happens, also when you say buck, what do you mean excactly, when i turn on either the ac or the lights at idle, my cars rpms will drop maybe 200 or so but a couple of seconds later it is back to normal

 

An S2000, My apologies for the typo . I meant my MAP sensor. As in I've replaced it after getting a CEL, after the "whack" not doing any good.

By "buck" I mean a very irratic acceleration surge from an even application of the throttle. The car feels like you're feathering the throttle on and off when all I'm doing is giving it normal amount of gas to accelerate. Once you turn off the A/C the car operates normally.

Any Ideas?

 

Anyone?

 

Is this thing on?

 

12-1300 is high. 800-1000 is normal

 

check the IAC lines again to make sure you don't have a leak, move on to the eletrical side (battery, alternator)

First though, allow the ecu to adapt.

 

sounds like battery or alternator if it happens with your headlights as well.