flat spot between idle and acceleration

[_the_mechanic]

I have noticed a problem with my 02 liberty manual rx wagon . When cruising, there seems to be a flat spot between minimal acceleration and my foot off the accelerator... it is a big nuisance especially when i use cruise control, it becomes jumpy when cruise is active down a hill when it is trying to maintain constant speed. I have driven 2 and they both have the same problem. Does anybody know what causes this and how to fix?

[KiDo_Tuning]

I have noticed a problem with my 02 liberty manual rx wagon . When cruising, there seems to be a flat spot between minimal acceleration and my foot off the accelerator... it is a big nuisance especially when i use cruise control, it becomes jumpy when cruise is active down a hill when it is trying to maintain constant speed. I have driven 2 and they both have the same problem. Does anybody know what causes this and how to fix?

It is the closed loop to open loop delay. Not much can be done unfortunately

[_the_mechanic]

Ahhh... bugger... thanks for the reply

[west_minist]

Was it always there?

[_the_mechanic]

Has been since i brought the car... 2 others that i test drove done it as well... alot worse than this one... i thought it may have been something to do with warn engine mounts or maybe backlash in the gearbox. Just trying to see if other people have had this problem before.

[_the_mechanic]

Maybe my original explination was a little incorect... it is hard to explain what the problem actually is... in my head everything points to engine mounts... when i am decelerating in gear (2000 rpm aprox) the burble from the exhaust is also felt with a bit of a bounce/jolt in tune with the burble... like the car is unsettled or loose...

[Veldex]

That amidst sounds like a bit of a fuel delivery issue. Is it running rich/lean at all? Try a change in an O2 sensor if that is the case, or a clean of your airflow meter with some carb/throttle body cleaner.

[west_minist]

Once the AFR is good and all leaks verify, the switch that Kido mention is correct, but the switch maybe causing a large switch in AFR causing you to feel this. Its possible a minor tune could help. Posting a log could help show us what you feel. Just log the following and post the log here.

Accelerator Pedal Angle (%)
A/F Correction #1 (%)
A/F Learning #1 (%)
A/F Sensor #1 (AFR)
Coolant Temperature (C)
Engine Load (4-Byte)* (g/rev)
Engine Speed (rpm)
Feedback Knock Correction (degrees)
Fine Learning Knock Correction (degrees)
IAM (multiplier)
Ignition Total Timing (degrees)
Injector Duty Cycle (%)
Intake Air Temperature (C)
Knock Correction Advance (degrees)
Mass Airflow (g/s)
Mass Airflow Sensor Voltage (V)
Throttle Opening Angle (%)
Vehicle Speed (kph)

[_the_mechanic]

Turns out that its a stuffed dual mass flywheel/ clutch plate... brother brought an outback and the old owner described the exact problem, replaced it with a solid flywheel and new clutch and it was sweet