Compressor? So you're saying it has A/C and that's when it gets slugish?
2.5L's weren't really designed for having A/C. Some YJ's had it but it was a Dealer installed option and did not come from the factory that way. Since the 2.5L shares all of the front accessories as the 4.0L, they used 4.0L parts on the 2.5L. The worst was if you has A/C and an Automatic. The Auto already wastes a lot of power because of the way it's designed. Add A/C and it becomes really slugish.
Now with the TJ's, I guess A/C was popular and everyone sorta expects it these day's. A/C was a standard option from the factory. It stills bogs the engine down though. The A/C system should have a vacuum controlled idle boost control. (I don't rememebr the exact name.) What it does is bumps the RPM's up at idle when the A/C is on.
Hope that helps.
My YJ has an AC on; I use it only in the summer, as the heat here in Miami gets out of hand otherwise, but my idle is still fine even with the AC on. When the complressor engages, the idle drops, but it immediatly comes back up (obviously there is more load on the engine, so the throttle is adjusted).
I do loose about 1 mpg with the AC on, so with gas being what it is not (about $3.50 a gal!), I will not turn the AC on until I start weating!
