OK, apparently I got my sensors mixed up. That's what happens when you only know a little about cars to begin with, and then don't go under the hood for anything more than an oil change for a few months.

Anyway, new results:

Pulled the MAF sensor. Doesn't look to be very dirty, but at Blackarrow's suggestion, I will spray CRC Maf Sensor Cleaner anyway.

Tapped the IAC sensor, and nothing happened (sadly, I don't have or know anyone with a scanner).

Unplugged the TPS. RPMs dropped about 200-300 RPMs, and when I pulled it back in, they slowly climbed almost 1000 RPMs, which put them even higher than before I removed it.

Another thing that was interesting was when I put my car in reverse to partially back it out of the garage, the RPMs were very quickly fluctuating about 800 or so RPMs. Again, it kind of seemed like it wanted to stall. As soon as I put it in neutral, it stopped doing that and didn't do it again, either in Park, Neutral, Reverse, or Drive.

Herc, I know you mentioned if the RPMs drop when I unplug the TPS, the TPS is bad. Does what it did sound like it needs to be replaced?

*EDIT* And, if I do replace the TPS, which one of these from Advanced Auto Part should I pick up?

Bump for suggestions?

I'm not a fan of throwing parts at issues but in this case if I was in your shoes and I unplugged the TPS and the rpms dropped 200-300 then I'd buy a new TPS and go from there.

I had an 89 Ford F-150 with a manual that had a bad TPS. The truck wanted to idle at 2000 rpms. Talk about fun limping it home trying to feather the clutch. Replaced the TPS and the rpms dropped back to a normal 900 at idle.

Well, I replaced the TPS and sprayed the CRC cleaner on the MAF, and now my car won't even start. It'll crank just fine, but it won't catch and fire up.

Like I said before, I had been having trouble getting it to start but I just figured it was because it's doing a lot of sitting.

Installing the TPS is as simple as taking the old one off and putting the new one on, right? Nothing I missed there?

I'll take the new TPS off tomorrow after work and put the old one back on and see if it'll start then. In the mean time, do you guys have any other suggestions?

*EDIT* What makes this even more frustrating is when I put my car in the garage, while it was hard to start, the RPMs were more or less fine. Drove it around the block, and while it still shifted hard, the RPMs were only slightly high. WTF?

Sorry about no replies my cpu bit the dust had to wait on newegg to ship another. In my problems with it gas wasnt present when just idling and if you havent had it out of the driveway for a while the gas would have evaporated. it doesnt take long especially around the heat from the engine. take a couple of laps around the block and then check it again. make sure you are hitting the gas pedal though and not just rolling around.

Ok, update: I took that TPS back and got another new one. Car starts now, but it still takes it a couple seconds, and I usually have to have the gas pedal at WOT for it to catch.

It also didn't fix anything. Sometimes it idles fine (why I don't know) but it usually idles real high, and it never shifts unless I let off the throttle.

However, when I changed the TPS it did finally give me an SES light, code P0123. That code? Means there is a problem with the TPS. Grrr. Googling it also told me that it could be a short in the wiring. I'm at work now, but I will follow the wiring and see if I can find any problems.

In the mean time, does anyone have any other suggestions?

And one more question....is driving it going to cause any further problems? I'm not driving it much, but to work and back, which is 10-15 minutes each way yesterday and today.

Ace, you do realize that when you reinstall the TPS you need to have that little coil spring wound like about 1/8 of a turn. Kinda weird... my buddy said he didnt do it how you're suppose to and had really weird shifting/throttle response.

I'm pretty sure I did it right. When I put it on, I twisted it about 90* clockwise first, then put it on and rotated it back counterclockwise so the thing in the throttle body would catch the spring in the TPS. does that sound right?

I know something was up with my old TPS because on the new one (both of them), if I twist it further counter clockwise it will spring forwards if I release it. My old TPS would stay in place, so the spring was obviously broken or something.