Surging engine

[riverman]

Has anbody ever had a problem with their car engine surging when you turn on the heater or A/C, my fans on the cooling system will turn on and then my engine will surge every couple seconds. It's a 96 GT 4.6L

[Laffs]

When was the last time you replaced the IAC?

[riverman]

The car idles fine when the ac and heater is off, it only surges wen I turn that stuff on. The a/c does not work in the car, it only started when I tried too add a can of the a/c stuff, just wanted to see if the compressor would turn on.

[Laffs]

Oh. That would be most likely the cause. Probably not enough freon in system so the system keeps kicking on and off causing the surge.

[maxwell6]

Sounds like AC compressor trying to cycle mine does the same ever so slightly. And my AC works fine.

[Old Fart]

When was the last time you replaced the IAC?

IAC = Idle Air Control

[riverman]

Found out what the problem was with the surge on the car, it was the a/c compressor. Low refrigerant in it, and also has a leak, will not hold a vaccume.