High Idle with a/c on?

[swnkylaxplyr]

My car has never had a good idle. I've fixed a couple boost leaks, but there is still at least one that I haven't been able to devote time or money to fixing lately. That info may be just coincidental, but may have to do with my new problem. I threw a new condenser in my car to fix the a/c but now whenever the a/c is on my idle shoots up to 1500/1700 rpms steady.

What could the problem be? I have considered the IAC as the cause of my bad idle previous to the a/c problem - all the coils tested out fine, but the actual actuator was very loose and sloppy. I threw a new IAC in, but there was no difference. It may be worth mentioning that it has been hard to start the car for the first time each day when not warmed up - could the IAC possible be stuck closed or something?

Another thing I have considered is that the ECU is bad. The guy I bought the car from said that he had brought it to a shop to have them tune it but came away from the shop afterwards with the feeling that they did not really know what they were doing. The only things I haven't done to try to fix this idle apart from that last(?) boost leak (intake manifold gasket I believe) is to block of the FIAV or throw a new ECU in it.

Any guesses guys?

 

[Blurred Talon]

I'm not sure off the stop of my head but A/C will bump the idle up.
Fix all your boost leaks though as that will effect your idle.

 

[swnkylaxplyr]

I'm not sure off the stop of my head but A/C will bump the idle up.
Fix all your boost leaks though as that will effect your idle.

I know that the leak is definitely at least partially to blame for my erratic idle, but I'm almost positive that it is not the reason that the idle jumps 600-900 rpms when I turn the a/c on . To me it seems as if something is overcompensating for the extra load that the compressor demands, but I need help figuring out what component that would be.

 

[crimsondragon]

Does your AC work now?

 

[swnkylaxplyr]

Does your AC work now?

Yes it is.

 

[crimsondragon]

I'd mess with the FIAV first. My AC idle didn't work for shyt before I closed the FIAV valve. After I did, my AC idle actually shot up like it should.

 

[swnkylaxplyr]

Haha well that is the exact opposite of my problem - I need my idle to stay where it is or even go down once I turn the a/c on. I do agree with you though that I should close it since it could be a reason my idle is erratic. Unfortunately I just moved away to school and I have none of my tools, so it may be a while before I can give that a try.

 

[Bluedragondsm]

The idle has done this on every DSM I have owned which would be 3

 

[crimsondragon]

You don't have a hammer, screwdriver and needle nose pliers at all? You can substitute a hammer for a giant rock and a screwdriver for a long bolt. You just need something to knock the freeze plug out the TB. The pliers are a must though to close the valve.

The FIAV is...funky, to say the least when it has 10+ years on it. It's pretty much a miniature thermostat and we all know how well those work when they fail on the coolant system. Close the valve and forget about it. The inconvenience of holding the gas pedal down on those cold mornings are worth the trade-off for simplifying the engine.

 

[swnkylaxplyr]

You don't have a hammer, screwdriver and needle nose pliers at all? You can substitute a hammer for a giant rock and a screwdriver for a long bolt. You just need something to knock the freeze plug out the TB. The pliers are a must though to close the valve.

I was under the impression that the throttle body needed to be taken out and then taken apart in order to get to the FIAV.