RPM surge at 70

[Ziesemer]

Got a 03 WJ 4.7 and have an issue on long trips with the RPMs jumping 200-400 rpms at 70mph. Seems like it is going in and out of OD. It only does this when i take her on long trips 3+ hours. Anybody got an idea?

[silver_laredoSE]

Had the same thing going wrong with my 04 wj. Its the torque converter locking and un locking. I was told that this was just an annoyance problem and nothing that bad. I replaced my TPS (throttle posistioning sensor) but before that I found that if I would push the pedal to the floor once or twice it would cure that problem as if something was just sticky and it would unstick...Ive also heard that a switch in the brake system can cause thisandcan be tracked down by trying to lift up on the brake pedal with your foot while driving.

[Ziesemer]

Thanks...I had a tran pan leak and got that replaced. Maybe i was low on tranny fluid that caused the converter to act funny. I haven't been on a long trip since. I'm going this weekend...cross the fingers. I am also experiencing a low idle issue where the rpms drop from 600 to 400 at idle. When in park or N or the AC is on it idles fine. It only drops when in gear and the AC is not on. I order a Delphi IAC valve...maybe those two issues are tied together???

[flyboy14295]

The next time your driving, while you have your foot on the gas, use your right foot and tap the break just enough for your brake lights to come on. See if that is what your feeling.

If it is, then it's usually the TPS, at least that's what happened to me.