Our 97 Suby Outback Wagon (5spd) with 146K miles has an annoying "herky jerky" hesitation at low speeds in 1st and 2nd gear. It is a PITA in slow traffic - its as if there is a learner driver with clutch control issues

 

Accelerating at higher speeds (45 to 50 MPH) I note that there is some minor jerkiness.

 

Any ideas?? Many thanks,

 

Andy

How long has it been since you've replaced plugs and wires? Or how about your air filter?

 

My car acted similarly when the MAF was toast, but that was abnormal in most people's opinions.

How long has it been since you've replaced plugs and wires? Or how about your air filter?

 

My car acted similarly when the MAF was toast, but that was abnormal in most people's opinions.

 

plugs and wires replaced 30K miles ago when we replaced the head gaskets. Air filter was replaced a few thousand miles ago.

No answers here, just wrote to say that I have same problem with my 97 outback been happening for months/years (190K). Plugs were replaced recently. Problem still there. I'll be watching too for any advice.

I have 2001 Forester with 82k on it. I get the same hesitation, herky jerky action. My bro (mechanics ear and feel) says there is a slight ignition miss at idle. So I am going to start by just replacing the spark plugs and air filter this weekend to see if that fixes it. If not the cure, next I will replace the spark plug wires. Note: I would pull the valve covers and replace the spark plug grommets if I find oil up in the wire boot as that can cause ignition miss. If none of that works, I will replace the O2 sensor or MAF I guess. Will post back here with what happs. Here is the discussion re the sp.plug grommet leak of oil into sp.plug wire boots:

http://www.ultimatesubaru.org/forum/showthread.php?t=24449&highlight=spark+plug+grommet

This is a common problem with late-model Subies.

Have you tried to search on this thread for 'hesitation'? You should get lots of hits.

Fuel problem_

 

I find my car runs best on the RON95 that it is rated for.

 

Upping to 98 has given me hesitation problems at full throttle. It\s as if the ECU gets too busy on the timing and cannot think fast enough and then retards timing just to be safe.

 

 

Those are EURO octane ratings....

By low speed, do you mean idle speeds? Eg, idle up to 1000 rpm maybe 1500 rpm?

 

If so, try a MotorVac, or something similar (perhaps Seafoam for the DIYer). The Phase I 2.5L engines are known for running rich and can occasionally have carbon problems. I know... I've faced it twice now with my 97 OB. The second time, it was being aggavated further by a lazy O2 sensor. Changing that solved the issue, eventually.

 

Note that if your problem is this bad, the over the counter stuff probably won't do much. You need an "industrial strength" cleaning.

 

If you are having hesitation at 3000 rpm, that's another whole issue. Usually knock sensor.

 

Commuter