My 93 Ford Crown Vic, is revving high

DRIBBLES777

MEMBER
1993 FORD CROWN VICTORIA

I have a 93 ford crown vic, V8 4.6
The other day I got off of the freeway and when I stopped at a light it stayed reved up, I could let my foot off of the gas pedal and it would continue to go.
If I press on the gas and get up to 35mph, it will slowly keep going when my foot is off of the gas. I let it sit overnight, a friend told me it might be the TPS (throttle position sensor) so I went the next morning to get one, and the car was fine, until I reached 30mph, and started doing it again. So I found out it could be the throttle body sticking, so I cleaned it real good, took the overhead off and did it all, started it up and it was perfect, put the overhead back on and started doing it again. I even checked the air cleaner and it was fine. My friend had changed the TPS, but I am not sure if he might have fried it somehow, or what.
I know it ran fine with the overhead off and now with it all together it's doing it again.
We looked for a vacumm leak and couldn't find one.
Mind you I am a girl, that doesnt' know a whole lot about cars, but I know I cleaned the throttle body right, I had someon on the phone with me while I did it, someone that I trust alot. But they live a little distance, and by time I was done he was at work.
So I need help.
Please.
Thank you.

1 Reply

RUDPRO

MECHANIC
224 POSTS

The TPS could have been damaged or could give you high idle if it wasn't installed right. To install it:

Disconnect the negative battery cable.

Line up the rotary tangs of the sensor, over the throttle shaft, rotate the sensor clockwise to the installed position.

Install and tighten the screws. Make them good and snug, don't overtighten.

Connect wiring harness.

Connect negative battery cable.

If your friend is sure it was done right, I can tell you how to test it with a digital mulimeter. You can get a cheap one for $10 at Walmart.
Doublecheck the throttle to see if it's sticking. With the car off, operate it by hand and see if it moves freely. If all that checks out, it could be the Idle Air Control Valve. I could tell you how to test that with a digital multimeter. Is your service engine light on?