THE CARBY ...

So why won't the car idle at less than 1500rpm (and even then very poorly).  And why are the spark plugs so black??

Well, lets start with the idle cut off solenoid.  I've played with carbys for years on my old cars, and I've NEVER come across one of these idle cutoff solenoids (or if you like 'anti-diesel' valve) that actually works!!!  This one turned out to be no different.

With the car running at idle, unplug the wire from the idle cut off solenoid.  It should produce a tiny spark as you pull the wire off, you should feel & hear the solenoid click, and the car should stop running.  Usually nothing happens except the tiny spark.  In order to get the car to idle at a lowish idle speed, without it being a really rich mixture, you'll need to remove the guts of the idle cut off solenoid.

The piston you see is from another carby I have.  Simply remove this and screw the idle cut off valve back on to block the passage left behind.  The car still wouldn't idle.

I removed and cleaned the jets.  The idle jet was blocked.  The car is now idling much better, however not well enough.  This is because the choke mechanism is jammed on.

I've completely slackened the chock off and adjusted it's cable so it's not partially on all the time (this explains the black sparkplugs & rich running).  Still the car is  idling a little high for some reason....  Well actually there is a reason, the 'high idle' valve for the air-conditioner, it appears to have been adjusted so it's always in operation.  I've backed it's adjuster off a couple of turns.  It should only work when the air-conditioning is switched on.

How the high idle adjuster works is by applying vacuum pressure to the valve (ie: the reason for it's hose).  This then mechanically wedges the primary choke of the carby slightly open.  

FINALLY !!!!  ALL DONE!!!  A nice smooth 800rpm idle!!

However here's another interesting point.  A LOT of Citroens (and most other cars) are fitted with twin barrel weber carby.    These carbies tend to burn the cars down due to the tubes the fuel line clamp to blowing out.  This is a well known problem, however all the specialists haven't even wired or properly  tied these tubes down!!

Just tying the hose clamps to the carby itself will stop the fuel lines dropping out.  However I"ll use the threaded tapered fitting shown under  'ID19' on this site.