Car: 1.7 88' 340 saloon manual.

Fault: When starting on choke with COLD engine it starts almost immediatly, runs for 1 or 2 seconds then conks out, exactly like fuel was being cut off. Tshh Tshh... Bruuummmmmm m m m STOP.

Will get a video if it helps.



With warm engine its one touch and starts, no accelerator no choke, just turn it.

CO level was 0.01 ppm.
HC was 0.06 ppm at MOT

yes it idles lean, no doubt about it. but the start stop restart thing.. could it be the carb flange has warped?

That is lean!
You could always try turning your adjustment screw a quarter turn at a time to see if it cures it, if it does'nt just turn it back.
My sisters car is doing this at the moment but have not got around to adjusting hers yet but my wifes used to stall under harder braking, I adjusted the lean mixture on that and cured that problem and only took a quarter of a turn. Will have to have a look at my sisters car so when I get chance as hers is really lean also going by mot which was lower then the wifes car.

With some of those figures I'd be expecting the exhaust valves to burn out pretty soon.

Right'o on the cooking valves, I'll get right on it, thanks man!
I'm sure my local garage will let me use their co meter for 5 mins If I ask nicely.

its only at idle, the mixture seems fine when driving no pinking going on.

I would think the cold starting problem is due to an over eager vacuum pull down on the choke, as the engine starts, its opening the choke a bit too far and the car dies off again. You need to measure the choke gap whilst pulling down on the vacuum pull down. I'm afraid its not very easy to describe but basically put the choke full on, and then push down on the white lever that has a screw on it just under the carb top. That will open the choke flap, measure that gap and it should be as in the specifications, from memory its about 4.5mm or so.

That seems to be what it is, I'll adjust the carb properly and see what happens - it's been running really good apart from that, mate said it was very nippy and he's been bombing around in a new beamer all week