ThirdGenRX7

Today I pulled up to a stoplight and the car simply forgot to idle. The rpms dropped like they normally would except that the drop didn't stop at idle, but instead continued until the car was off. This continued until I got to where I was going. So I parked the car and walked around at a car show wondering what the hell was going wrong with my idle. I go back outside and start the car, and it idles perfectly. I noticed that the water temp was in the 160's. Next stop light water temp was in the 170's and the car wouldn't idle, it would just die like before. So i sat in quite a frew lights so the water temp got up to 190 degrees, and the car would hold an idle but it was really rough. Then I parked the car for a few hours and watched a movie, came out and started it and it idled perfect, as soon as the water temp got up to the 170's it would get an extremely rough idle but this time it held it, almost sounded like it was missing or something. basically what I figured out is that it idled while cold and hot but not inbetween... I have a pfc and that's one of the few things that I think could be messing with the idle? but I don't know why it would randomly start being screwed up? anyway hopefully somebody can help... thanks in advance and sorry about the essay

7-sins

I would like to know as well... I am having somewhat of an idle problem and any info helps.

luneytune

My rex had a strange idle much like yours. Do the idle adjustment procedure by the manual. First make sure the idle speed screw is backed out to not having an effect its near the throttle position sensor. Turn off engine - on the Diagnostic connector use a paperclip straightened out to a "U" and insert it between the "TEN" and "Ground" points. Start the car (should already be warmed up fully). Now adjust the idle air screw - under the intake pipe use a mirror to see it, it is quite recessed and big. Adjust to the top of the range 740 or 750 rpm - idle should be very smooth. Then pull the paperclip link - idle will settle ,again smooth. Push in the clutch and put it in first or 2nd gear - idle should rise slightly but should not drop if it drops it usually needs to be adjusted again in my experience. I wonder if a bit of oil condenses here and changes the air sometimes but I usually have to do the procedure twice. Hope you have a manual. Good luck!

7-sins

I will have to try the paperclip thing... what does that simulate on the engine?

ThirdGenRX7

what section is it in the manual?

luneytune

Manual Section F-16. The grounding of pin "TEN" with the paperclip takes the ECU out of the picture. No correction for fan or engine load etc. By the way forgot to mention make sure all your electricals are OFF like AC, Blower, lights and stereo. Otherwise the RPM will be too high after setting and all electrical loads are off. Page 17 explains the workings. See attached FYI - sorry file too big to upload.

ThirdGenRX7

i'm a little confused about this paper clip thing... is there a diagram somewhere that I can follow? also why is it necessary?

luneytune

What more can I add? If you don't have a manual, download section 7 Fuel system and Emmisions system from the "scud...." site, not sure how to spell it and have lost the link.

The paperclip shorts pin "TEN" to ground which is required to set idle see page F-16 and F-17.

luneytune

bump!

ThirdGenRX7

what I was confused about was where I was supposed to jump it... I see the diagram on page f-16 but is it in the diagnosis connector? also why do you have to do that?

ThirdGenRX7

nevermind i'm an idiot you said that already... sorry