Re: engine jerk (archive)

when i left off the accelerator, but it is still in gear, i sometimes get a small surge or engine jerk. it wont happen when i have the accelerator pedal depressed. i have changed out my main fuel pump. i notice the the accl. cable connected to the throttle is damage(plastic or rubber damage). could the cable be getting caught, because sometimes i notice that when i press the clutch in the rpms take a little longer to come down to idle speed.(like it is getting stuck).
alex
88 m5

Since you have yet to include the engine RPMs, gear and or road speed, I'll give you a WAG.
The A/C compressor is switching on?
Also the DME has a coast-off function which shuts off the injectors when the throttle is closed and the engine RPMs are over 1200. Once the engine returns to below 1200 RPMs the injectors will switch back on. Depending on the CO and idle setup(open loop setting vs ICV) the transition could be abrupt. You should be able to observe the coast-off RPM by holding the RPMs above 3K(in neutral) then letting off quickly and watch for the tach to hesitate(also some engine shake) in the RPM drop to idle. You may also want to check/set the CO and open loop idle speed to help the coast-off and idle function.
The E-34, M5 has no parking lot manners due to the fact that the coast-off is at 1500 RPMs which is at an RPM that is useful in parking lots while in 1st gear. The bucking at low RPM transition of closed to open throttle can be reduced by adjusting the throttle switch so the throttle is shut when the switch closes.

Follow Ups:

Rod ? for you, Re: engine jerk sheldon 09:12 6/27/2001 (2)
- Re: Rod ? for you, Re: engine jerk Rod 09:38 6/27/2001 (1)
  - yikes. Seth 12:54 6/27/2001 (0)

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