Michiana Jeep Club

Ok, have a weird one. Randomly when I start my jeep, or maybe when I go to shut it off, the engine will rev to roughly 3 grand and sit there, sometimes a second or two and drop, sometimes several minutes.

Also, associated with that - but maybe not, randomly as i am driving the rpm's will jump around, almost like it's trying to change gears. 99% of the time it does not do it during acceleration, or under wide open throttle, usually when im just driving along minding my own business. Sometimes I can stomp on it while its doing it, and it will knock it off.

It throws no codes during any of this.

Last night I changed the throttle position sensor with one I had from who knows when and who knows what Jeep. I took the throttle body off, cleaned some of the carbon out of it, cleaned the idle air control valve. It was pretty clean, I mean geesh I only have 88k miles on it. NOW it threw a code, but most certainly has to do with the unknown TPS I put on it.

Any ideas? I usually run 87 octane, last tank I ran 93 with no change. This started several months ago I've just now decided to take the time to look at it.

TPS would be my first suggestion to fix your problem. Second is don’t run 92 in a motor designed for 87, it will not get a complete burn of the fuel and cause carbon build up in the combustion chamber and on the back side of the valves.

try your tps sensor and maybe even try your intake air temperature sensor. on a dmm or a scantool

I suppose I should have mentioned this was resolved about 6 months ago. Thanks.

allright my bad, what ended up beeing the issue then

Finch wrote:allright my bad, what ended up beeing the issue then

derek never found out , he just sold it
sorry derek had to say it