Gosh, I feel like a total newbie asking this, but its been giving me a strange feeling in my gut. I recently got a 1990 Mazda RX-7 GTU, when I start it, it does that quick warm up where it shoots to around 3000 rpms for like 10 secs and drops back down to around 1500 rpm. For non mazda cars, an idle of 1500 rpm seems a little to high, is having a idle of 1500-1300 rpm for my model of rx7 normal. Thanks for the help.

 

That idle is pretty high, usually the problem is a simple vacuum leak. Maybe from Dry rotted vacuum lines or old worn gaskets. Read the FAQ at the top of the 2nd gen section, it should have some idle diagnostics. And plenty of other ways to remedy problems with your car.

 

It's got this information in the FAQ section. I'd check there.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/frequently-asked-questions-2nd-generation-rx-7-faq-fc-494667/

It says it's supposed to idle at around 750.

Edit: Whoops. Someone beat me to it.

 

ok well check the tps and see if it is in spec (check fc3spro.com) if it is within spec try playing with the bac. if it still a little weird i guess check and make sure your cas is set right.

**edit** damn two people beat me to it! both are good answeres too .

 

It's vaccum leak; I had the same problem before and a simple replacement of hoses will do it.

 

Well, my biggest hope is that it will still pass a smog test so i can get it registered, is having this high idle cause me to fail.