I know alot of you has had this problem before and theres alot of causes for this, please share your experience.

 

A/C button being on.

 

mine does it sometimes... but only the AC button is on but the fan (0-4) switch is in the off position.

 

Many causes such as:
1-bad O2 sensor
2-air leak
3-too many mods
4-improperly adjusted TB
5-bad or improperly adjusted TPS
6-improper fuel pressure

but since this problem occurs way too much even with stock engines
7-lousy Mazda idle control logic in for the ECU is the main reason.

If you have a PFC and DL and convert to manual idle control, the problem goes away.

 

try adjusting the TPS, it helped alot of us who had this problem, heres a link to it:
https://www.rx7club.com/forum/showth...1&page=1&pp=15

thats if you are sure that there's no air leak or whatsoever.

 

Could be a vacuum leak, faulty ISC solenoid, wax rod assembly, dashpot, tps...

 

If you have the lights on (or any electrical load) and are in neutral and shift into first or second and have big idle fluctuations that go a way when you put it back in neutral, look to your clutch switch, the one on top of the clutch pedal that adjusts the pedal height. Replace it, mon

 

idle air control may be gumed up

 

I had to remove my airpump, when I put it back forgot to hook up wires, idle fluctuated like mad till I realized what I had done, hooked wires back up good to go.

 

Low compression