I was checking my TPS today with my digital miltimeter, and I was really confused. I didn’t think it was out of adjustment by very much, if at all. The car runs fine, it just has a low idle (500-600 RPM) I was testing it because the write-up for adjusting idle says you should. I was a little concerned when I didn’t get any voltage reading on either side, so I adjusted the screw clockwise. I went in half turn increments, but it took 3 full turns before there was any voltage reading (is the voltage supposed to be consistent? mine was jumping around from 1-10 volts). Also, when there was a voltage reading I could hear one of the vacuum solenoids near the oil filler neck (the round one on the left) clicking randomly.

Thinking my TPS was shot, I tested its resistance with the throttle closed (1.29k ohms) and wide open (4.63k ohms) this is pretty close to what the write-up said it should be.

So do I need a new TPS? I just wanted to get my car to idle nicely, now I am stuck scratching my head. <- me

 

Oh, and I forgot to mention that it still runs just fine, even with the TPS turned in 3 turns from where it was.

 

If it was me, since it is running fine I would not worry too much about it. The way I noticed mine was bad is when I tried to feather the throttle the car would sputter almost like it was running out of gas, but once you stepped on the gas a little more it would smooth out. Swapped out the tps and she is running fine but will also idle around 500rpms at times.

 

Yeah, I had all day at work today to think about it (my job is mindless) and I am thinking the reason the voltage was all over the place is because the green test plug contacts are pretty corroded. After all, they have been just sitting in the open for 20 years, probably just wasn’t getting a good connection.

 

That is where an analog meter is nice, just wanting to know if there is current or not. I use two little light bulb testers you can get for $2 that work from 5v-120v ac or dc (something like that).

 

Read the tps adjustment for dummies thread in the 1st gen archives. it shows you how to build a checker that works really well. ( I made it and use it. Time well spent. All 5 minutes of it )

 

I agree completely. After reading the thread and doing the simple adjustment, I managed to CURE a severe backfiring problem that I had for 15 years.

Steve