tps ? lot's of them

ok just replace my main ground cables, old ones were shot. So I went to check my tps volts on engine side .80. The volts on tranny side 3.80 should be around 5.00 right? so my question, is the tps shot? When i first start it when cold it idles around 800-900 rpms once it warms up it idles around 1000-1100rpms. also it like surges when cold a little. I checked my vac lines, all good no leaks. Now someone screwed with the throttle stop screw, not me last owner, is there a factory setting for this? I do have the comfort power switch would that effect the volts at the tps? Real crappy gas mileage too. It's an 87 4.0 aw4.

someone enlighten me I don't want to spend the $$$ right before christmas. Unless I have too.

Thanks

I'd say your crappy mileage is related to an O2 sensor, bad/leaky injectors, or you need a tune up. TPS wont have much to do with that. The rough idle might be more IACV related...did you clean that?

Yes i did clean it injectors are newer and tested 2 months ago just did tune up today. I am not sure if the iac is working is there a way to test it? It also doesn't seem to shift right it will go into 4th around 40 It used to shift right at 35

The poor idle and change in shifting points to a TPS problem. An analog meter is the best way to check it as you can move it through the range and check that the voltage is changing smoothly.

You say you've checked the vac lines, so that's not likely the problem. If the idle screw has been messed with and you can't get the idle to come down to normal, you may need to back it out a little - maybe 1/8 to 1/4 turn. I don't know you to properly set it. Most likely there is some spec for sliding a feeler guage past the butterfly when fully closed. When I swapped the throttle arm on mine as part of the tranny swap, I had to back the screw out 1/4 turn to get the idle back down to normal.