Fast idle racing when hot.

[sallmark]

Fast idle racing when hot.

So I have an issue that when the engine is hot, it races very fast. It mostly happens on hot days but now more often since I have fixed a fuel issue. (now running a electric pump, new Tank, lines and pressure finally correct at regulator.)

I have a 1986 1.9 Petrol, DG with Pierburg 2E3 Carb.
Start is fine on the van, the flap is closed (3mm gap) when cold start and when warm is fully open so I feel the new Auto choke is working fine and the New pull down unit is also working fine, as I read these were possible things to try.

Could it simply be that the fast idle needs adjustment since I have put the new auto choke? Is there a fast idle adjustment that can be made when warm? Somewhere I read its can’t be adjusted and some forums mention a screw! 9 on the pierburg diagram. I’ve read so much different advice I’m in a forum spin!

I can’t work out where my fast idle adjustment is done. I can find the adjust screw what alters the fast idle on the choke below the step cam but where do you adjust fast idle when its up to operating temp.

Could the distributor and Vacuum advance be causing an issue with the fast idle?

Any pointers greatly received!

[CovKid]

Check along the length of throttle cable first. Its not unusual for outer sheath to become snagged or misaligined, particularly if any work done underneath. Sometimes sorting that will restore normal idle speed. I know because mine is doing exactly the same and I've never altered screw on carb. Plan to get under and check its path front to back. Invariably its somewhere around where cable enters engine bay or above gearbox.

If it idled fine before, its likely to be that.