Is my car stalling? Stalling in gear, but showing RPMs?

[MCNPathfinder]

Good evening! Had a question I was hoping someone might have some ideas about. My car has trouble staying running if I pull it out of gear like when I'm nearing a stop light or something. That I have a few ideas about, but this evening it's doing something new. I replaced the radiator today, pulled off the front bumper cover and air filter area body cover. My intent is to put an OEM bumper back on, so I left them off and was driving around.

I was driving in 5th gear, and all of the sudden lost power. It sounded like the engine quit, but my tach still showed RPMs. When I put my foot to the floor nothing was responding. A second or two later it came back to life and started responding to the accelerator pedal presses. For all intents and purposes, it felt like the engine had stopped, but must've been still moving to register RPMs? It happened a few more times. Note that I never pushed in the clutch. It did this while in gear.

I know I need to fix the stalling at stop signs thing, but I thought this might be something different. Anyone ever heard of this before? A thought I had was maybe the MAF isn't use to that colder air without the body cover being on? It was raining, so maybe some water got into some electrical connections? Not sure...

Thanks in advance!

[sns00]

I think you'll have to do some dirty work before anyone can start to have ideas; it could be 1 thing or 5 things at once.

Did you check battery, MAF, PTU, alternator output, vacuum lines? Did it happened again on different weather?

[MCNPathfinder]

Thanks for the response, and sorry for the delay. After some further research, I think my car is idling too high at a cold start. Somewhere around 2k RPMs.

I started at the TPS. From my understanding, with the throttle closed, the hard idle switch should show continuity AND my voltage output should be around .4-.5 volts. I can't seem to find that "sweet spot". Continuity on that oval plug also shows about the 9,000 ohms it should be.

Is it common for these TPS to go out? It didn't seem so, but it kind of seems like that's part of my overall problem?

[sns00]

In my experience the TPS dont fail often.

My next step would be, provided everything checks with the TPS, IACV, IAR is boost leak hunting
and fuel system checks.

What year? N/A or TT? Any ECU codes?

[MCNPathfinder]

I ended up picking up a 14-pin diagnostic reader. From some of the Wikis, it looks like this might be an easier way to troubleshoot? I noticed that it seems to happen when I'm barely touching the gas pedal (more or less to hold speed). I'd imagine it's probably right in that sweet spot where I can't get the hard idle switch to be in the right spot with the .4-.5 volts on the TPS.

In any event, it's actually working pretty well now. I do still need to tear into it and clean things up. The car is a vacuum nightmare. I've found a few things that have been bypassed "properly" (meaning to say forum/community approved), and a few things that are random hoses with bolts plugging them. Can't help but think it's an air metering nightmare.

I have a '91 NA. Was going to change the timing belt out this weekend and try and take a look at some of these things, but FedEx lost my parts so that's fun...