I have a 1988 RX-7 GXL ( non turbo ) , 13B injection , the car was running fine when I parked it a few months back , Now it will crank & idle well , but it starts to surging when I rev the engine above 1500 rpm . I cannot drive the car around unless I stay in low gear. I have cleaned the throttle body as good as I can . I checked the TPS ( throttle position sensor ) with a volt meter & it seems to be fine, it is getting 5 volts DC to the TPS & the wire going to the main control module voltage goes up & down when I rev engine up & down. I have also checked the BAC valve & it seems to be doing ok ( I ran a jumper wire to the connectors & it clicked like the FSM said that it should ) , The vacuum lines are pulling a vacuum. I am at a loss of what to check next. maybe some of you guys have experience this before. Oh & here is a strange thing that is happening , I can turn the A/C on & the engine will rev up to about 2500 rpms before starting to surge up & down. I am new to working on rotary engines . Thanks for any help guys

 

Welcome to the board.

Have you tried:
1. adjusting the idle
2. looking into the thermowax

Also, here are some Surging idle threads that you can browse if neither if those two ideas work.

 

thank you for your suggestions Diabolical 1 , I will try both ideas ..... jackthelad43