rolling 99 jeep

I purchased this 99 laredo from a used car dealer I was referred to. The dealer had a shop replace the motor with a new crate 6 cyl, rebuilt rear end, new starter, ac gone through and various sensors replaced with one being the TPS I beleive. The Jeep seems to run pretty good and does idle around 750-800 rpm but wheather motor is warmed up or cold I can't hold an idle with the gas pedal, it jumps from the normal idle to about 1300 rpm. Is this due or could be due to the TPS not installed correctly or is it something else?

Just Another XJ from AK

Start by looking for manifold vacuum leaks. Then check your fuel pressure. After that, things become electrical.

rolling 99 jeep

I'll check the vacumm lines but for fuel pressure test I'll have to find someone with a gauge or get one if there not exspensive. Thank you.

freegdr

If it idles fine why are you trying to keep idle with gas pedal ?

scottmphoto

Yeah, it's supposed to idle @750.

rolling 99 jeep

Don't you think it's rather odd that you can't hold an rpm between 800 and 1300 on any road vehicle? But if you must know why freegdr, to run some test. Thanks for asking.


scottmphoto, the problem isn't the 750 idle. It's when I want to raise throttle slowly it jumps to 1300 rpm. I can hold it there but when I let it off as to got to say 1000 it goes straight to normal idle. No control of pedal idle between 800 and 1300. Thanks for letting me know what the normal idle speed is.