AC bogs down engine
 

Have a '94 RX7 Auto. just bought it and don't know much about the rotary's ...yet. The guy I bought it from said he had problems with it bogging down when he turned on all the electrical items (AC,radio,lights,ect) so he brought to Mazda and they replaced the (forgive me if I mutilate this, I can't recall what it's exact name is) "engine idle/throttle controller" ($700) part. This did nothing. So then they thought it might be the electrical system. They screwed with that for about a month and then finally (i guess it was down to, screw it, lets just try anything) they changed the AC compressir and that seemed to work. Well today I noticed that if the car is in "Park" and I turn on the AC, no problem....but as soon as I shift it into a drive gear, the idle slows down and will sometime kill the engine....Does anybody have any tips on what to check?

how many miles do you have on your car? you might want to run a compression test. I have heard that when you have low compression on an automatic, it sometimes causes the engine to die at idle. The engine cannot take the extra strain. You may want to start looking for a good remanufactured engine!

There's only 55,895 miles on the car. It idles fine when the AC is turned off, and it idles fine when it's in "Park" and the AC is on. It only has problems when in a drive gear and stopped and the AC is on.

most 3rd gen. motors only last about 55-60000 miles so yours is probably about ready to go! the only way to know is to have a compression test done. you may have to face the facts that you may need a new motor pretty soon. the engine cannot handle the additional strain of the A/C and the auto. transmission.

My auto had the same problem - for a while leaving the fan switch on 3 or 4 helped prevent stalling - but as my compression got worse so did the stalling - I got quit good at hitting the AC button as I came to a stop to prevent stalling:D - Auto motor usually go 80-90k + before needing rebuilt (mine went to 103k before finally blowing a water seal) - get a compression check and do a THROUGH Search for vacuum leaks, both agrivate the problem. :rolleyes: