Been going through some tough idle problems, lots of stalling on deceleration, developed into surging and seeking. Got worse and worse until on the way home one day it was stalling at anything under 2000 RPM. So I've got to throw it into neutral and gas it at every stop light.

I tried to adjust my TPS using the test light that I made. I've done it before without any trouble but this time I couldn't find a spot where only one light would stay on.

It goes straight from no lights to two lights every time. I thought it might be my test light so I tried using a volt meter and it shows the same thing. No volts on both and then BAM! 10 volts on both. At the point when it switches from on to off I can hear the relay going crazy.

I checked my TPS itself and it's showing .5K to about 12K as I crank the throttle.

Any thoughts? Thanks in advance.

 

Probably time for a new TPS, I hate to say it.

What happens over time is that the TPS gets worn out along that section of the carbon path from the scraper being in that position for so much of the drive time (over 30yrs!), and it ends up wearing out the resistive path that the switch follows. I have a few TPS that I've swapped out, and I always mark them with a #, so I can keep track of which one is the previous version - I'm on #3 right now, and the car is starting to hunt at idle again (could be 'idle surge' if you want to search here).

Start there and you'll likely have your culprit. Good luck,

 

N236-18-911 is the part number.

 

Thanks for the input. Sucks when the best place to start is a $200 part...

 

I remember from way back that was a Mitsubishi part and it was used on many early 80's chryslers and such. Just opening the clamp you could change the sensor to use the rx7's mount. If I remember right it was like a $20 part.

 

Can anyone explain the function of the adjustment and how being worn out could be affecting it. I checked it again and the resistance is within spec.

 

Mine is bad too. How do you check it? Can you do it with a standard ohm meter.

 

Still much cheaper than a series 5 TPS...

 

The series 5 is just 2 of the same sensors. I'll have to find the part number but if I remember right all 2.x non turbo chryslers from the 80's used the SAME part. Quit wasting money and do research

 

I'll have an s4 TPS available soon. You'll need to fasten an OEM plug back onto it from the factory harness as I was playing around with it on my haltech with a weather pack connector

Does the -SE TPS only do the bottom 15-20% of the throttle throw? If so it should work.

Part numbers are slightly different but I think you'll be able to make it work

 

the function of adjustment is to have the ECU indexed properly to the throttle opening. the TPS does a few things, the first is to enable the idle area/map in the ecu.

the TPS also runs the two air control valve solenoids, and the distributor vacuum advances.

the plunger design of the sensor doesn't seem to be very consistent, and the sensor requires periodic adjustments. it also doesn't help that the ECU takes the throttle reading very literally, the later ecu's are like +10/-10% with the tps