1990 Sportrak High Idling.


Reading previous Posts tells me that high engine idling speed is a somewhat common problem, but no-one seems to be able to supply any answers to it. My Sportrak was fine until it went in for the dreaded MOT, and now it idles at around 2500rpm. The tester swears he adjusted nothing, yet something has obviously changed!! I do have some mechanical knowledge, but the (over?) complicated vacuum system associated with the carb has got me beat! I can reduce the idling to near normal by adjusting the screw that is beneath the throttle mechanism, and is only visible when the throttle is held wide open, but this results in bad starting from hot. The engine will only start if the throttle is held on full whilst the engine is being cranked, and stalls if the revs are not kept high for about 15 seconds or so. Cold starting is as normal. Any clues/advice/hints etc would be most welcome - it's a pig to drive as it is - nothing like its normal self!!

fast idle

i don't have a carb on mine it's efi but with my other cars i would say the MOT man has caught a pipe somewere and the engine is sucking in air.double check all the pipes before you start upsetting other setings.

Fast Idle

The vacuum sysstem is a nightmare on these carbs, but all pipes seem intact, and I can see no unused open ports anywhere.


Any possibility the accelerator cable is snagged? Check the foot peddle all the way to the throttle.


Thanks for that, but it was the first thing I checked - there is slight slack at the carb end when the throttle is shut.

Post your model but try this.

What model is your Sporty?
Ive just had a quick look through my w/s manual. It suggests that electronic systems are very robust but cables/connectors could be the problem. First check all electronic connections for security and corrosion. Then run the engine and flex/wobble each connection since wires do deteriorate within the connectors. Any flexing should jump the short and point to the problem.