I mean, it could be a lot of things. Hard to know where to begin our if I should just let the shop deal with it.

well if its just a stuck throttle that's a pretty easy fix

What year make and model?

@JesseJames 1995 Mustang 3.8L.

If it means anything, first I noticed it was rolling down the other side of a bridge in 3rd at 35, so revs were a little high, I was using the higher revs to help keep my speed down.

When I put it in neutral at the traffic light I noticed the revs were still up and I was like... Uuhhh... Wtf?

@Pinochetball Maybe that means something to you.

I would remove the throttle body and clean it with throttle body cleaner. And remove the mass air flow meter and clean it with MAF cleaner.

Yeah like a i said last night youll wanna remove that plenum and visually inspect the tb to make sure its not sticking open, and remove the iac to make sure the pintle isnt sticking open

Btw is the MIL on?

@Pinochetball No MIL

Btw, since the IAC is what the computer uses to adjust the TB, shouldn't the problem have gone away when I unplugged it?

No lol the computer adjusts the pintle in the IAC on idle to keep it smooth so it doesnt surge. If its sticking open, like mechanically stuck the ecm wont be able to adjust it and the idle will be high

Most the time when they stick they stick just a little open and the car surges or it sticks shut and it wont idle at all or it will but super low

If the cars at 2000rpm unplugging it wont matter anyway because youre off idle

Ill be at work in a few mins and ill email you some Identifix test plans real quick so you can mess with it today

To bad it isn't obd2 would be much easier to pinpoint. But I agree I would start with tb and or iac

@JesseJames It is OBD2 but all I have is a basic code scanner.

Also there is a sticker on the TB that says not to clean it because there is a special coating.

If it's the IAC pindle sticking that's causing this, should physically removing the IAC from the TB and then starting the car make the symptom go away?

@Pinochetball ^

No dont do that lol

Youll have massive unmetered air

The car wont even start

Ok if the TB says not to clean it, then just make sure nothing is keeping the blade open, but id take that IAC off and clean it real well

Sorry i didnt get a chance to send you any test plans, today was busy as shit

That's alright.

So you pulled the MAF pigtail and the car ran rough?

@Pinochetball "Pigtail"? I unplugged the sensor, and yeah, it barely ran.

Lol yeah pigtail is just what i call the connector ends

Thats ok tho thats a good sign actually

I'm still not sure how to tell the IAC valve from the TPS. I know you said the TPS was the big aluminum thing on top and IAC is just a little plastic piece on the side, but I'm looking at some YouTube videos and it seems like they're calling the big one the IAC, but sadly I can't find a video of someone doing this on my exact engine.

Oh, another thing I noticed today: A popping feeling in my accelerator. When it's all the way up and I press down, there's a tiny little pop, like I'm overcoming an infinitesimal amount of resistance.

Yeah I'm looking up pics of the IAC on AutoZone.com and I'm pretty sure the IAC is the big one on top.

Is there any way to know for sure if it's the IAC before I clean it? Cause I don't have full confidence that cleaning it will work, maybe I don't do a thorough enough job, or it just doesn't work and what it really needs is replacing. But I'm not sure how to test it. @Pinochetball @JesseJames

Usually, you should be able to pull the IAC off, keep it plugged in, and have a friend turn the key to just the "on/run" position (not start it) and you should see it move a bit

Also, what kind of little handheld code reader do you have?

Most of those, even the little cheapos, you should be able to see the long and short term fuel trims

Just some $20 Advance junk that tells you if there's codes and which monitors are ready.

A 95 model is obd2 they got it before the v8 models. You should be able to scan it and retrieve any stored codes.