Hi everyone.

Car has 155k miles engine rebuild at 45k.

Vacuum hoses were stock black rubber baked. Some were thin low quality blue silicon. I replaced all of them with thick silicon hose. Replaced check valves, purge control valve, and two solenoids that broke nipples.

Reinstalled and started car.

This was all prompted when during a freeway trip home the car would bounce idle from 2500 to 3000 at idle or clutch in.

The exh warning light came on once I got home.

Now the car idles at 1400 to 1500 and still sounds like it is hunting. I have adjusted the idle screw the aas screw. Checked the maf sensor visibly, unplugged the isc valve and it idled smooth at 1400 and started to hunt again.

I have no idea how to test the tps and to be honest would like to avoid taking it off again. I replaced all gaskets too.

Monday the car is heading to ricks rotary.

Any insight? I just want to understand this problem more. It is a 93 rx7. I've read countless posts. Here and elsewhere and the fsm.

Here is a video of the car but not the problem.

 

Thats strange, how long have you had this car for?

 

First step in troubleshooting idle is to adjust the TPS. Always. If the ECU can't reliably tell the car is at zero throttle, it won't be able to idle. Additionally are you sure there aren't any vacuum leaks? Water sprayed around the engine bay can help isolate leaks while the engine is running.

 

I've had this car for 3 weeks. I took it to ricks rotary in pleasanton california and have been updated. First iwant to say the speed and quality of service by Rick and his staff is incredible, I really recommend them. They checked my adjustment screws and did a smoke test. Adjustment screws were set and the idle came down to 1000 but the engine should have died at those settings. The smoke test showed no leaks. Rick said it was very unusual and that he would check the tps next when the engine cooled down. My car has some leaking and beaten bushings all over. Sorry I'm not a super technical type to know exactly what he said. I'm just super happy that I did a good job on the vacuum hoses.

 

Fairly sure the TPS has to be checked with the engine fully hot on the FD. So that the thermowax is not holding the throttle open.

 

You reminded me now that the thermowax for the coldstart system was sticking. I was also told the throttle cable needed adjustment. I'm trying to understand this stuff as much as I can.

 

x2 on TPS triple check!

 

check tps with volt meter on ohms and look up specs unplug it and place voltmeter +- on terminals. you will need wire diagram to