I recently bought a 90 GXL and swapped in a S5 motor out of a 91. Everything seems fine other than the car wont idle below 2k. The water temp gauge isnt working though. I checked the plug on the temp. sensor and it seemed to be on good, so I assume it's the temp. sensor. It's the green plug behind the alternator. There is also a green wire that was either cut, or pulled out off the clip, but it is not connected to anything. It's coming off the wiring harness just to the right of the alternator. Any ideas??? Also, OIL PSI gauge is not working either. I realize the problem could be a bad sensor or thermostat, but has anyone had this problem before?...

Why is the idle not coming down to normal?

What is the mystery green wire?

PLEASE HELP....THANKS!

 

have you checked the TPS out at all?

as far as the wires go Im not sure what that green wire controls...


Oh and really its not an S5 swap if the car is a 1990 - haha

 

haha, yes i know a 90 is an S5. I was just stating that to clarify that it still had a motor from a s5. but no, I have not tested the TPS yet. I will if nothing else works, but I'm pretty sure the problem is related to either the cold start wires on the transmission that we changed out, or the temperature sensor. Since the gauge isn't working at all I would assume that would be part of the problem. But then again, we are talking about an RX7.

 

Thermo Wax Pellet...

 

i seriously doubt the thermo wax pellet is the creator of this problem. all that does is allow oil into the e-shaft once it reaches a certain temp. i guess it's trial and error time. thanks anyway.

 

the thermo wax pellet has nothing to do with the oil in the e-shaft. Its on the back of the throttle body and the coolant heats it up and lets it idle after the cold start.

 

To make a motor run you need 3 things - air, fuel and spark. To make an engine rev you manually vary the amount of AIR it injests, the computer calculates how much of the other 2 you need. If the TBS and idle air bypass are set correctly and you don't have any vacuum leaks, no combination of fuel and spark alone will make it rev at 2k.

Thermowax is for cold starting, basically a choke / fast idle setting thing. Assuming everything else on the install went normally, I say check your throttle cable and see if you need to slacken it some or if it's binding. ~Rich