Thread: TPS problem???

A faulty vacuum or IACV will cause a rough idle until warm if your idle is funny as well. Check into that.

He is having a driving issue when the car is cold or starting to warm up. It miss fires for a bit then goes. I bet this happens between 1000-3000 RPMs.

This is not vacum leak.

Doctor's diagnosis then? Don't leave him hanging

I'll almost garuntee its your tps sensor, try disconnecting it and see if it the car hesitates less in the beginning (but connect it back cause your car will run better with it at its normal temperature) < just a diagnosis.. My Tps sensor is absolutely shot... My car runs better without it.. For example when its connected, my car will practically hesitate for seconds at a time.. i have a gtir motor, and these parts are hard to find for a reasonable price

Yep! I guess is a common problem. Like I said, the only thing that I have not changed is the TPS.

I will try to do what sr20brian said to see what happens.

Check the voltage to see if its set .45 TB closed and .55 TB open.

Well, I give up. I disconnected the TPS when the car was cold but I can't run it. Is worst when you disconnect it. Back to square one.

Give me a few days and I will look into it for you. You will have your answer by Monday.

I have heard of issues with the connectors under the high-port manifold, causing bad idle, when they are full of grease or the connectors are loose for the water by-pass valve and the engine vacuum switch, under the mani.

Additional problems with skipping idle, can be related to a bad distributor cap.

If you have never taken off the manifold and cleaned the tar from the bottom of the rib-roast, of the intake runners, there could be a clogged vacuum, for the very same switch, but from inside the manifold.

Also, check your Idle-air valve and PCV, as these may be clogged or blocking your vacuum, causing the ECU to read a lean condition, when it is not.

I have never heard of a worn throttle body bushing, but the old carbs used to wear the shaft-bushing, and when it leaks, at start-up, there is an in-accurate air reading, due to leaking shaft bushings. Those small vacuum switches under the TB can cause problems with the recirculation can, and vacuum issues then cause idle issues, but just at start-up.

Replace the gasket at your IACV and clean it well. Do not change the settings!

Then go over the connectors, under the manifold, in the same area.
Chances are, you have a loose connector under there and a vacuum leak someplace else. Are the relays under the TB in good shape?

I haven't take the manifold off, and I'm sure is pretty dirty inside. Maybe that is the problem, Should I use Seafoam?