I'm having a small problem with my AC; whenever I turn it on, and let the engine idle, the car dies.

The car idles normally at ~750 RPM without the AC on.

Could this be a TPS issue?

Should I adjust the TPS with the air on or off?

Any advice will be appreciated.

 

More likely BAC.

PaulC

 

The BAC is messed up. You should take it apart, and clean it to see if it helps. If it doesent, use the Factory Service Manual (can be found online) to test it. If it fails youll need a new one.

 

Please excuse my ignorance; BAC means what?

 

Actually, I had a guy bring his 7 over with the same problem. Once I adjusted the TPS, it went away.

Rat

 

I have a similar problem, but the rotary guru I took it to traced it to a problem with the throttle body (after checking compression, BAC, plugs, wires, filters, TPS, etc.) Ended up adjusting the idle up until I can get a new TB. Those are some things to check. You can get copious amounts of info on all those things (especially BAC) by searching here in the forum, a Haynes Manual and of course the FSM's at http://www.fc3s.org/

 

on the turbo's there is a valve in the back of the intake manifold, the air supply valve that should turn on when you turn the ac one. its sorta like the bac valve, it lets more air in to raise the idle. i have seen them stick before, it could also be the tps.

mike

 

While all these suggestions could be right..

Especially the TPS suggestion.
I bet you this is the actual problem.

I doubt that the BAC is the trouble.

Its only doing whats its told. (assuming its working at all)

I can fix the problem. PM me to meet.
Your in Atl, Im in Atl.

I'would be happy to fix this and show you how I did it.

 

Hey sniper could you maybe send me a pm or emai- kleach18@hotmail.com - telling me what to do. If you could that would be great? Until then I am going to try and adjust it with voltmeter and see if that works.

kleach

 

http://home.rmci.net/panther/tps.htm

Here ya go!

 

Thanks J-Rat

I went ahead and messed with the TPS and got it set but it still dies when I turn on the AC. I replaced the BAC a while back so I know that is not it. Could it be maybe a signal from the ECU or something?

 

Hmm..Did you do the light method or the voltmeter method? I have had better luck with the light method, but other people prefer the other way. All you do is adjust it so the first light JUST comes on. Could be your initial idle/air settings, or a timing problem. Have you changed the motor or done anything else lately?

 

Read this article: http://www.teamfc3s.org/info/articles/idle.html]

Read the part towards the bottom about the bac and the output of the ECU.

With the car warmed up and idling, pull the plug off the bac. Did the car drop significantly in rpm????? If it did, then that means your bac is working, BUT....your idle is not set properly to 750 rpm. Go to the manual and install the initial set coupler and set you idle to 750 per the manual.

Did the idle stay the same when the bac plug was pulled off???? Put the plug back on and then turn the a/c on. Did the idle increase a bit, say about 100 rpm??? It didn't did it. Fell on its face like you described did it not. Then read the article in the url above and determine if the signal from the ECU is being put out. The bac might be just fine, but no output from the ECU is the cause of your problem. Read the article in the url in this post again. If the transistor is burnt out in the ECU, the cost of the transistor is about two bucks. The degree of difficulty in replacing it is not huge. I've done it. Also SEARCH for the name AKAGEALS. He wrote a thread just last month describing his fix of the ECU and the degree of difficulty.

And just incase someone who is interested in trivia: You can start your car and let it idle. Then take the bac plug off the bac(if your idle is really set, the car will not stall) and install the plug on a fuel injector. The injector will pulse. I write this because at times I've seen people wondering how to pulse their fuel injectors off the car. Pulses at about 125hz I believe. Works on a 87 car anyway. If you have a newer car with oval plugs you would probably have to make a jumper.

READ THIS ARTICLE:http://www.teamfc3s.org/info/articles/idle.html