Having an issue with my MR200 ST with as the title says, bucking and jerking. This happens when I let my foot off the accelerator. It is most noticeable at low engine RPM in 1st and 2nd. Less so in the higher gears at higher speeds but still noticeable. I canít crawl along in traffic without constantly dipping the clutch to prevent it looking like Iím a learner on my first lesson
my engine was recently rebuilt after the crank had to be repaired and a couple of rods replaced along with various other internals. Previous to this I had to have my gearbox repaired but that was about 3 years ago and I had no issues after this. Throttle body is lovely and clean, I have no exhaust leaks (not that I could find). Iíve also tried resetting the KAM just in case it was a TB issue by removing fuses then leaving out for a while and then idling the engine for 10 minutes and then taking it for a short gentle drive. Iím thinking could it be a vacuum leak? Could it be engine mounts? Could it be something far more sinister (hope not). Or maybe a fuel delivery problem with the pump? Spark plugs were changed around 4000 miles ago. When the engine was repaired the battery would have been disconnected for a fair while would this have somehow affected the ECU at all?? Only other things Iím aware of are a quiet whining noise that starts just after the engine has found its idle point which increase with engine RPM. It also becomes more noticeable when I put things on like heated seats and the window/mirror heaters so maybe something to do with the alternator. The whining isnít the PAS. I had this replaced in January and the fluid is still pink and makes no noises when I turn the wheel. Plus I know what a bad one of them sounds like from previous repairs!
Any advice or info anyone could give me would be much appreciated.