'88 rx-7 67k miles on re-build...basic re-build, no mods..everyday driver...recently replaced all engine belts...2 days later replaced alt...after re-charging battery and replacing alt, started car...after it heated up the idle dropped and started bouncing @500 and sounded rough...during warm-up idles perfect @1500...I have my warm idle set @ 1000 normally...just replaced plugs today, the old ones had been cleaned once and re-used...same problem...rough idle after the car gets to normal op temp...car has ran great forever until I replaced belts to remedy a belt squeal on takeoff...maybe "timing" off...how do i check the timing...heard at one time you have to get a special timing light for RX-7's...if so what kind and from where??? Thanks in advance

 

I'm going through similar timing/idle issues...
Check out this thread from FC3S, it gets a little technical, but helped me understand timing much better. Here

And heres a link to my current thread where I'm working through it if you so desire to read through it too...Here

As for a special timing light, from what I understand, if you are going to CHANGE the timing, i.e. advance/retard the timing then you need to use a 2 stroke timing light instead of the normal 4 stroke timing light. My understanding is that this is because being that the rotary has spark every 360 degrees, and a 4 stroke has spark every 720 degrees, you cannot use a 4 stroke timing light.

HOWEVER, if you are just using the timing light to set the timing to the factory "notches" on the crank pulley, so long as you keep the timing light at 0 degrees, you can use a regular 4 stroke timing light.

 

I've got the same issue with my car right now too. The thing runs perfectly until it gets up to operating temp. Once it's at temp the idle is really low and rough. I've also noticed when I come to a stop the idle sometimes drops so low that all of my warning lights come on and it comes really, really close to stalling. I can't bring my idle up by adjusting the screw on the top of the intake either. I'll have to do some digging and see what I can come up with.

 

Before you turn the screw on top the intake to adjust the timing, you have to ground out the check connecter on the drivers side of the engine compartement. The same connector is used to ground out so you can count the engine light flashes and adjusting the tps. I couldn't get mine to adjust right either until I did that.

 

I've grounded that out and it still doesn't make a difference. I think I've got a BAC valve problem.

 

The connector that is to be grounded to adjust the idle is the green 2-prong connector just in front of the drivers fender well, correct?...years ago when I replaced the idle screw on the intake, last owner used lock-tight or something on it...broke when i tried to adjust it...after replacing the screw, i did'nt ground out the green connector and the idle adjusted from @ 750 to @ 1000 with no prob...the idle has stayed @1000 until I replaced belts & alt...how do you check "flashes" for TPS with the green connector on the driver fender...Also, in an earlier reply it is stated to get a 2-stroke timing light instead of a 4-stroke...as in 2 or 4-stroke motocycles right?

 

It's my understanding that you need to use the 2 stroke timing light if you are checking timing advance and timing split. There was an article about timing on the FS3pro forum about that. I read it twice and still don't understand it, but give it a shot. To check the flashes, I'm assuming you mean fault codes, ground out the check connector by the r/h strut tower. It should only be a one pin connector and count the number of times your check engine light flashes (S5). long flashes count as ten, short flashes as one. ie Long, short, short, short = 12. Then check the FSM manual for what the code means. In the case I demonstrated it's high band TPS.