For some reason, when i turn on my ac my car does not idle like its going to stall out. But if I turn the ac off, then it seems like its going to stall out. Any ideas? I think its the vavle on the intake manifold, thats a little dirty, think i may need carb cleaner....So what you think? Let me know.

 

How low does it idle with no accesories on?? I know that there is a different way to set your idle with all the accesories being on maybe it isnt bumping up the idle enough when you do turn it on? Sorry I cant be more help I never had that problem when I did have A/C and now I dont have it anymore so well wouldnt have to worry abut it now either.

 

when i turn the car on with no a/c it idles like it has wild cams and the rpm's go a little below 1, making it sound like its going to stall out. But if i turn the a/c on then it just runs fine. Its wierd as hell.....

 

how low is it idling with the accessories turned off?... it should be around 700 rpms... try resetting the idle, check the timing, and adjust the valves

 

its around there when its turned off......but it sounds like it has wild cams....plus usually when it gets that low, it seem like its going to stall out....

 

bring the car to my place, i'll fix.

 

pmed ya....

 

Well it could be your IACV otherwise known as the EACV. Also is your coolant bled with no air in the system? If your cooling system has air in it it can give it a weird idle.

 

From Vinceg99:

Yeah I would definately try to clean out the IACV. See if that helps I bet it would my idle flutuated like crazy up and down up and down till I replaced mine

well I do have one if you end up needing it. But I think that cleaning it out would do it if that is the problem those things tend to get carbon build up on the screens and such...mine was really messed up thats why I had to replace mine it was actually broke from when the IM got sent to me (I have a Z6 IM on my A6 head) otherwise another thing to try is like I said try bleeding your cooling system and make sure all the air is out

well basically flush the radiator...but you dont really even have to flush it there is a bleeder for it in the front of the motor where your upper radiator goes to warm up your car and open the bleeder a little if you only get coolant out your fine if you get air out that could be your problem if air does come out keep opening and closing it until there is no longer air in there. Or you could just take it in to get the cooling system flushed and they will bleed it for you but thats not necessary if your coolant doesnt need to be changed...

 

In addition,

well it could also be your TPS but checking that thing is a pita and to be honest I have no idea to do it but it has been brought up on HT before so you could probably find out the info you need in those threads

 

With the AC on, the ECU will increase the idle speed to compensate for the load the compressor places on the engine. With the AC off, your idle system is operating at fringe of it's control ability and that's what causes the loaping.

Some common causes can be a dirty IACV, (maybe unlikely because it does increase the idle with the AC on. A good idea to clean it anyway), vacuum leaks, and a dirty/malfunctioning FIV (fast idle valve). The FIV is on the firewall side of the intake manifold. It has a cover held on with two phillips head screws and a large vacuum hose running to it. Pinch the hose shut with pliers and make note of what happens to your idle. If the idle smooths out, the FIV is leaking. Take it apart and clean it, or replace it.

 

 

Perfectionist you are the bomb diggity....will be trying all these things when i get home....

 

my friend told me that it might be a simple sensor adjustment......hopefully....still tryin to fix....

 

havent tried anything yet....get back to yall when i do...thanks for all the help....

 

try some stp gas cleaner. happened to me when i pressed on my brake peddle, then my idle would drop below 500. when i put the stp in the idle goes up pass 500 to compensate for the power. before i put it in the idle would first go down then back up then back down again. just an idea.

 

its went to the shop....now fixed...dont know what they did though...still need to ask....