I have an idle problem on
My 89 fc gxl, whenever I turn the ac on the idle drops to almost a stall. Not surewhat's up any ideas:0

 

I'd be interested in the solution to this problem as well. Mine not only bogs down but it will occasionally stall.

 

Turning on the AC puts a load on the engine. Normally, the ecu compensates for it by upping the idle speed via the BAC. Do you have the BAC? You'll need to check the signal to the ecu telling you the AC is 'on', a functional BAC, and good wiring between the two.

Temporarily, you can adjust the idle speed higher to compensate for the bog.

 

What pin would the bac connect to on the ecu? And is it as simple as wiring the two together

 

Mine will stall but it's rare that it does :[

 

Pin 3Q for an S5. Blue/Green wire.

 

I will try this today my good sir thank you

 

The other BAC wire is B/W and it receives battery voltage from the Main Relay w/key to on (and start).

 

Awesome , are these the only connections?

 

^ Yes.