you have got some slack in the cable when the carburettor is at idle? I had a car once that the previous owner had done everything to idle it down, closed the mixture right off, the whole hog, and I found the problem was no slack in the cable in the idle position, thus keeping the butterfly open...... 5 minutes, then it idled beautifully and didn't have any stalling issues when stopping at intersections.

 

Your problem though is it not shutting instantaneously when at what, maybe you have a vac leak? plug the pcv line and see if it improves, tighten the manifold bolts, check for anything loose or hoses cracked.....

 

Our PCV was drawing that much air (with a lynx manifold and pair of su carburettors) that it would idle to about 1800 rpm with the butterflys closed....... upon removal (and venting to a catch can instead) I found that the idle is now good.

 

Robert.

you have got some slack in the cable when the carburettor is at idle? I had a car once that the previous owner had done everything to idle it down, closed the mixture right off, the whole hog, and I found the problem was no slack in the cable in the idle position, thus keeping the butterfly open...... 5 minutes, then it idled beautifully and didn't have any stalling issues when stopping at intersections.

 

Your problem though is it not shutting instantaneously when at what, maybe you have a vac leak? plug the pcv line and see if it improves, tighten the manifold bolts, check for anything loose or hoses cracked.....

 

Our PCV was drawing that much air (with a lynx manifold and pair of su carburettors) that it would idle to about 1800 rpm with the butterflys closed....... upon removal (and venting to a catch can instead) I found that the idle is now good.

 

Robert.

 

I had a look earlyer today and the cable does have a bit of slack on idle position, it idles at about 1100 rpm nicely after a few secconds to warm up. at intersections etc it's fine. only when ur driving past 20kmph ish that the throttle sometimes sticks on, and when i change gears it stays on so it revs the engine a fair bit when i push the clutch in. I'm sure it's not th pedal either. it could be the cable is old and brittle or springs not so sure its the carby. when i slow right down it doesnt do it only occasionally.

 

Cheers.

i had the same problem with my ke30 throttle cable 2 years ago...and i found that the cause of this was the rubber cap in the cable on the side of the carby...yes this made the cable to stack....i removed this and until today are all ok...check it....