do i need freon?? i just purchased the car and prev owner didnt mention anything bout ac. he sayed i t need a recharge or something i dunno.

 

Im not to sure about our systems but if we have a low pressure cutoffswitch if there was a low charge that would make low pressure and the ecu would turn off the compressor clutch and the engine would run like the ac was not on. im not sure how our system works i just ripped it out. I wish i could be more of a help but not having the system and knowing its operation im pretty useless. Um most systems have a input to the ecu when the ac is on to increase the idle to keep the engine running with the extra load of the compressor, but 3000 seems alittle excessive. ps..freon is r12 i think... the system is r134a.

 

the bac valve lets extra air in to up the idle when you turn the AC on. make sure its operating correctly. what rpm do you idle at normally?

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/howto-rough-idle-diagnostics-672127/ look at post #8 for instructions

 

just a note. when the engine is warmed up and running (like the fsm says) when you unplug the bac valve the rpms should drop. make sure thats happening.