Fast tick over

[else]

Hi Everyone, anybody out there help me with this one?

When I blip the throttle the engine revs drop to 1200 rpm for about a second or two before dropping to 900/950 and settling there. Its not really a problem until i am moving in slow traffic where the car becomes very jerky at that rev range.

I have cleaned the stepper motor and checked the idle screw as per Steve Heath's instructions in the bible.

I also tried disconnecting the vacuum advance but it made no difference.

It seems to be a fuelling rather than ignition problem so i am a bit stuck.

The engine runs at a constant 70 degrees when cruising and goes up to about 80 in traffic ( i have a Mod-Wise adjustable 2 speed fan kit that kicks in at 80).

Anybody got any ideas?

Andy

[tvrbob]

I know it's awkward but you must clean the stepper valve seat also. Cleaning the valve plug often works but if it doesn't then there's no option but to clean the seat too.