Club 80-90 Forums

Ive been trying to sort out my fast idle on a 1.9DG Pierburg 2e carb to no success.
I have checked all hoses and replaced, done a full carb clean and rebuild with the kit,
new fuel pump, lines filter and the spring is in tack on the choke.
Now, when i start first thing or from cold, it will cut out if not reved to get it warm, then runs perfect.
Had other issues last few days with second choke not opening till 3 or 4 seconds and bad timing.
Anyway, after a good run and warmed up it will idle very high at around 1200 by my guess (no rev counter)
The spring in the choke is moving the butterfly and i have the front idle screw wound right out so is not touching anything.
The plastic cap is still on the fast idle screw and i don't want to touch it as it must be something else.
When i first brought it home a few weeks back it was lumpy as hell but the choke worked from cold, and idle was slow.
So somethings gone wrong with me cleaning it and i can not figure it out.
Any ideas please?

Bit more info, had new plugs and replaced the limited rotor arm to standard, and did the timing by ear but checked with the pully method to see its about right.
I have adjusted the fuel mixture screw but to the better as it does not stink of fuel from the exhaust anymore.
I'm also doing 80 miles a day at the moment as its my daily ride and sat in traffic jams on the M62 is just burning fuel and getting the engine very hot!
It has only just gone past the centre line and about 3/5" so its normally well under half and runs very cool
Cheers

Been outside and checked secondary throttle unit by sucking on it.
It makes a noise as if working, the arm goes up but the flap at the bottom of the carb does not open.

CK Joiner wrote:Been outside and checked secondary throttle unit by sucking on it.
It makes a noise as if working, the arm goes up but the flap at the bottom of the carb does not open.

Yep - the flap doesn't move unless the throttle is pretty much fully open

ok thanks for that pal, just been reading even more old posts on this issue and the wiki again (been reading and trying this for a week now) and I've backed the choke right off or turned fully clockwise.
I have tried the pull down unit by sucking on a longer piece of pipe and nothing happens so ill order one of those