hi new to this site,
got a 2001 vectra 2.2 sri, when i change gear and accelerate the engine judders like you are on and off the throttle pedal very fast, seems to last for about 5 seconds then clears its self. does not do it all the time but more often it does it in 3rd gear on acceleration, ive checked for vacuum leaks and cant seem to find any, no wiring loom is touching any of the gearchange mechanism either. coil pack - crank position sensor - plugs - fuel filter are new. i did have fault code p1516 throttle body malfuction and have now changed it - no fault codes for 3 weeks now but problem still exists, had problem for 6 weeks now, any help be appreciated, thanks