Poor acceleration from a standing start. ****** fluid or something worse?

[AVR2]

My 2005 KJ Limited with 88k on it, which I've had from new, has developed an intermittent acceleration problem. Basically, if I need to pull away from a standing start quickly (such as joining a main road of fast-moving traffic from a side road) I can't.

You step on the gas and It's almost like it hasn't properly downshifted and it's trying to pull away in a high gear rather than a low one - you start moving really slowly. The ****** isn't slipping at all, the engine doesn't miss, the rev needle just stays low and climbs with vehicle speed. Once you've picked up some speed it's fine, and it still shifts gears smoothly. The best way to describe it really is like trying to pull away in 2 rather than 1.

I did some experimenting today and I think I've narrowed it down... it happens when you step ******* the gas from a standstill. If I press the throttle gently from a standing start, it pulls away completely normally with no lack of power, and *then* you can mash the pedal. Kickdown works normally at typical cruising speeds.

Any ideas as to what this might be? Obviously at the back of my mind I'm worried that it's a symptom of an expensive ****** problem, but of course it also could be as simple as needing some fresh ****** fluid or new plugs or something like that (it's overdue for its service).

 

[jake1234]

If you use one of those K&N type filters and you over oil them the oil gunks up the sensors and makes vehicles accelerate like crap.

 

[AVR2]

It's got a standard Mopar filter. And as noted, the problem only seems to occur when standing on the gas to get a fast pull-away from stationary.

 

[WesChapman]

During your testing, did you try manually shifting your transmission to 1st and then trying your full power acceleration?

 

[J-Thompson]

During your testing, did you try manually shifting your transmission to 1st and then trying your full power acceleration?

This is where I would start
if this fixes it then trans issue
if not look at plugs and fuel filter

 

[TwoBobsKJ]

I did some experimenting today and I think I've narrowed it down... it happens when you step ******* the gas from a standstill. If I press the throttle gently from a standing start, it pulls away completely normally with no lack of power, and *then* you can mash the pedal. Kickdown works normally at typical cruising speeds...

Sounds eerily like recent ****** problems in my '03 Renegade...

I had the same symptoms - and it was due to the overdrive clutch pack slipping due to bad clutches caused by a failed snap ring. The Jeep seemed to work normally until it came time to accelerate quickly - then the issue would pop up. The cause is in the clutch packs - specifically the OD pack works directly with the 2nd gear clutch pack and creates a cascade of problems with all of the packs. The long and the short of it for me: I needed a new ******... :shrug:

Take your Jeep to a reputable transmission shop and have the ****** completely flushed and a new filter installed - not just a pan drop. The flush and new fluid may fix your problem.

Have the shop drive your Jeep while having their computer connected to the OBDII. Ask them to show you the CVI numbers for the L/R, 2/OD and 3/UD clutch packs. Be prepared: If one/or a couple of the CVI's are out of range the clutch pack(s) are bad and you will need an overhaul or remanned ******.

I got very fortunate. I found an '04 ****** with only 37,000 miles on it and got it installed for $300 plus about $70 for fluid and a filter. Check out Car-Part.com for used trannies.

Not that you want to hear this now...but the scheduled maintenance helps to prevent big expenses. Now is probably a good time to do the differentials and transfer case oil changes as well. :blah:

Bob