idle drop when i use a/c Options

[99gt3sge]

ever since i swapped my 3sge in my sixth gen, the idle seems to drop below 900, there's times where the idle rises how its suppose to but then it drops again. i was wondering if any of you guys runing swaps have encounter this problem? could b my idle valve or is it controlled by the ecu?

[ricochet1490]

the a/c bogs down on the motor. Think in terms of engery. to idle the car needs "X" amount of gasoline which equate to say... for instance 1200J of energy. That 1000 J is say, 150J for power steering, 400 J for the alternator and the minimum fuel needs for the motor are say 450J.... which of course equals 1000 of your 1200 available joules. At this point the motor is spinning freely and at whatever your stock idle is. Mine tends to be about 850 for normal operation. When the A/C turns on, it zaps the remaining 200 J of energy available at that fuel trim, which means the flywheel energy isn't as much because the A/C is using the other 200J.

Basically what I'm telling you is this. the A/C WILL and does on my 6g and likely everyone elses 6g, slow the motor rpms even though you are using the same if not more fuel to power the a/c. 900rpm while the car is on with the a/c is from my experience higher that usual, but maybe is necessary for a 3sge because of the lighter flywheel or smaller displacement or whatever. my A/C being on sets my idle to 700 or below and a little rough.

So I think you're fine.