Surging / High Revving

[AR-Trvlr]

Hi All -

I just picked up a new(er) '99 ranger with the 2.5 - 115k miles or so. When I drove it home it would rev pretty high (no tach so no hard numbers) when I was shifting or sitting at a light. It would go up, then slowly drop down, then idle so low I thought it would die if I didn't goose the throttle a bit.

I checked the throttle cable / throttle plate, and it moves freely, so I'm guessing it's either a sensor or a vacuum leak.

What sensors are most likely the problem? Are the cheap enough that I can just change them out, or should I take it to the mechanic?

Any other advice?

Thanks!

 

[dmassey]

Hi All -

I just picked up a new(er) '99 ranger with the 2.5 - 115k miles or so. When I drove it home it would rev pretty high (no tach so no hard numbers) when I was shifting or sitting at a light. It would go up, then slowly drop down, then idle so low I thought it would die if I didn't goose the throttle a bit.

I checked the throttle cable / throttle plate, and it moves freely, so I'm guessing it's either a sensor or a vacuum leak.

What sensors are most likely the problem? Are the cheap enough that I can just change them out, or should I take it to the mechanic?

Any other advice?

Thanks!

Have you pulled any codes? You might check the throttle position sensor and the idle air control. If either or both check bad, they are easy enough to change if you are mechanically experienced. Chilton's manual has an excellent detail of how to check the sensors, etc and is not too expensive at Auto Zone or Advance.