Since your problem seems to correct itself, then this isn't likely the cause. But I'd check throttle and cruise control cables where they attach to throttle body. Plastic ends of sheath are breaking and can cause throttle to hang. In US there was a recall to install bent-wire spring clips to stop this.
Paul Shovestul

Originally Posted by
ktteoh
folks, here's what i have: when i change gears, declutch and taking
my foot off the accelerator, the engine rpm eithers surge another +500 rpm or so and hangs there for ~10-20seconds before dying down.
could these be caused by a failing fpr or the vacuum hose connected to the fpr?
.....Got to keep the loonies on the paath.