First off I wanna say thanks for looking.

So, Got the car running fine, readjusted the idle to be around 800 or so cold, and around 1000 warmed up. Why? Because I was stupid and did the TB mod years ago. After chasing down a loose Water Thermo sensor connection, I thought that everything was sorted. I took the car out, filled her up with gas, and did some redline pulls. Got home, parked the car, everything was fine.

Wake up to go to work, and yes I DD my 7 in the winter, and all of a sudden it's surging again and only revving to 1500. It would start, but not want to rev AT ALL. Foot all the way to the floor and it would still only rev to 1500 then stumble to 1000. If I let go of the throttle, it would die.

Unpluged the tps and nothing changed. All of my WHATTT?? What could it be?

Figured it might be the afm, but as I went back out to my car to check, all of a sudden It decided to start working again. Like nothing happened, just fine.

I figure it was just "it's time of the month", but I'd like to know what happened. So I can prevent it from happening again.

I'm going to check the ECU if and when it happens again, but I just wanted to get some opinions I guess.

Any input is welcomed.

 

Just did it again!

This time I kept it running. Magically, as I got to the ECU I heard the idle slightly change, and as I went back around to blip the throttle everything was fine.

What the hell is causing this????

 

Sounds like a faulty TPS. Or not adjusted correctly. Being as you have cold start removed, you can adjust the TPS while the car is off and cold. I prefer the multi meter way of adjusting, google search it. Very easy, also when it is properly adjusted assuming it works, you will have to help the car hold rev for a bit until its warm enough to hold idle. FC3S pro has a great write up on TPS adjustment w/ a multi meter. Hope this helps!

 

For throttle positioning sensor adjustment:

Start up the car and drive it or let it warm up until it is at full operating temperature. Turn the car off, then turn the key to the "ON" position. (Not "START")... Immediately get to the engine bay with your digital multimeter. Ground your multimeter's black wire. With the red (positive) multimeter probe, probe the G/R (green wire, red stripe). Check to see that the multimeter says 1V. If it is over or under, adjust the TPS adjustment screw until 1V is reached. The TPS adjustment screw is located very near to the TPS. It requires a flat head screwdriver.

A little over or a little under doesn't make a world of difference. Car warmth DOES matter. Try doing this very quickly, as not to let the car cool down too much.

 

Thanks guys, but I'm pretty sure it's not the TPS. Seeing as I it has been unplugged since last night. Even then, I made sure it was tested and giving out only 1 volt.

Anyone know if the O2 sensor can cause this? I'm just not sure if it could cause such a problem when the car is cool.

Driving around with the TPS unplugged while the engine was still cold, it was bucking like crazy. I had to pull over four blocks away from my house because it was so bad. So, I sat there for about five minutes, and the problem went away completely.