I have been having problems with my throttle plate sticking open on my TPI motor. It will stick anywhere from 1500-3000rpm, but if I tap the gas pedal real quick, it will go back down. So I figured it needed to be lubed, but that didn't help. So I then went to test the TPS to see if it was binding or just to see if it worked properly. This is what I found... from idle to about 85% throttle it climbed from .5 to 2 volts steadily, then all of a sudden around 90%, bam, 5 volts. 3 and 4 volts are nowhere to be found. Is that normal? I know its got the proper range, .54 - 5 volts, but is that jump normal?

 

It's supposed to be linear, meaning it increases steadily, not jumping around. I would say you should replace it, as it probably is part, if not all of your problem.

 

Before you go and replace it.

Spend about $2-5 and get a throttle body cleaner (aresol) and give it a nice cleaning. I just used a rag and my fingers. I sprayed it and cleaned the dirt away from the throttle body. You might be surprized on how much dirt and stuff that comes out of there. I used a tooth brush but I later read that you shouldn't because of the portective coating on the parts. Make sure to clean both sides of the butterfly and around the edges of it, thats why it stuck for me.

I cleaned it once and let it sit in my drive way for a few minutes to dry out, then started it up and let it sit at idle for a few minutes will revving it to see if it would stick. Then drove it around for 10 minutes. It did stick at first but not as much,(you need to be in an open area because of the smell and fumes.) Once i got home, I then cleaned it again, waited a couple of minutes and drove it around and it worked fine.Now i clean my throttle body every time I do an oil change, and i dont have to worry about it sticking anymore.

This worked for me and hope it works for you.

 

I had a problem with idle etc. as well and here was my issue with the tps. I had just switched to a Holley 58mm from a BBK 58mm TB. The linkage thats used to open the TB blades has a little arm that pushes down on the arm of the tps sensor and opens the tps. The arm that is part of the tps was rubbing against the TB. Had to grind it down a tad. Now it works fine.