I got a 94 rx7 and the only problem is the throttle. When the car is cold, everything is fine, although it idles at around 2500 rpm. When it warms up, rpm starts jumping up and down, If i rev it slightly, it backfires a little, ocasionally it would stall. Does anyone know what can cause this or what can be done to fix it?

I have read the 10+ pages about the idle problems, however a lot of the information does not make sense to me, especially the abbreviations.

 

when is revs up to 2500 rpm that's the AWS (accelerated warm-up system) kicking in so when it warms up it's supposed to go to idle speed which is b/t 700-800. when you say it is jumpin up and down, b/t what rpms? if it's backfiring it's prolly running really rich. how does it perform while driving?

 

sounds like the tps (throttle position sensor) is a bit off spec, does the car idle really low and tries to raise its idle up?
also does it stall when you let go of the accelerator or while accelerating?

 

please list what mods u have done.

 

mine doing this aswell. someone said to clean the tps. i did that, made no difference and it works fine as i tested it. then someone said it could be the vacuum problem. so ive deceided to replace the rats nest. and am in the middle of doing it. Some of them are a RIGHT PITA!!!!

 

It never gets below 1000rpm except when it stalls. When the car warms up, rpm jump between 1000 and 1500. It's driving normal, but when I stop at a stop light, rpm jumps again between 1000 and 1500 rpm. No other noticeable differences. Check engine light never comes on, I checked the bulb and it's fine so it should come on if there is a problem. When I try to rev the car I press the gas and it gets to approx. 3500rpm (I tried to go higher once and it wouldn't go past 4500rpm) when I let go of the pedal it would backfire and sometimes the rpm would fall so low that it stalls. I haven't done any mods yet. The previous owner replaced all of the vacuum lines, (there is one vacuum line pluged with a screw, I assume it went to the stock intake) installed greddy intakes. With the exhaust, as far as I can tell the downpipe is aftermarket 3", stock cat, racing beat single tip 3" cat-back, there is still a hose going from the cat to the motor somewhere. There is also an extra connector on top of the motor, I can't find a place to plug it in. It is under the pipe which goes from the turbos to the intercooler. Connector is blue in color. I just replaced the sparkplugs, transmission and diff. fluids.

 

What's the throttle position sensor (TPS) and where is it located? Does anyone have a picture of what it looks like? I'll try cleaning that, see if it will help.

 

It is on the back side of the UIM, next to the throttle body. If you are going to clean it, you will need to adjust it also. The adjustment is probably most of the problem.

Google for instructions on both, not too hard to find.