alright, i recently bought a 87 rx-7 that wasnt running. i got it running and it runs pretty decent but im having a few minor problems. The idle is killing me. when i first start up the car it wont idle at all, i have to keep it alive. then maybe 5 mins or so it will idle, but its not a steady idke. it will be between 1800 and 2200, a consitant, duaaa, duaaa, duaaa. (sorry for the bad sound effects). i have adjusted the idle screw on top of the car. when i drive, there is a hesitation at 3800 and other small ones, and just seems to be somewhat low on power. Ive checked the compression, and its good. its hard to check the timing with the way its idling, but i set the initial timing and i know its close. another thing, the shift light doesnt come on, i know it works cause when the ignition is on, the light comes on, but i can be cruisin in 2nd at 4000 and it wont come on. Also, when i push in the clutch it seems to change something when the engine is idling, it seems to be a little smoother. any suggestions will help. thank you.

 

first check for vaccum leaks

 

Your initial won't stay running problem could be a bad thermo wax which is causing the accelerated warmup system to not function. I am now sure about an s4 but my s5 starts and jumps to like 3200 rpms for about 10 seconds and then drops down to lower till it warms up and it is moved off the fast idle cam. BTW all this info is in the Factory Service Manual.

It could be a vaccum problem also.

Search for idle problems or Faq for idle problems

Your TPS and a whole host of problems could be related, so do a lot of searching and reading.

The Faq for Idle Problems will help out with eliminating things you will need a multimeter and patience.

Wlecome to the Forum and congrats on the 7 I hope you treat her right because in turn she will treat you right.

 

Probably vaccum. Otherwise check that the thermowax and elcectro-mo-throttle deal is intact on top of the throttle body.

 

Set the TPS to 1K Ohms, engine fully warmed up. See the FSM or run searches to see how this is done. Then set the idle to approx 750 rpm. If you can't get the TPS properly adjusted, you may have a bad TPS. If you can't get a rock solid idle, you may have a vacuum leak and they can be a bitch to find.

The hesitation at 3800 is related to when the secondary injectors come on. The problem here might be clogged injectors, stuck secondary actuators, or even a faulty ECU ground.

Start working and eliminate the problems one by one. These issues have been addressed many times in this forum, so searches should yield a wealth of information and suggestions.