Idle speed problems..
 

Hi all,
I've just got my '77 C3 up and running and have come across a few throttle 'issues'. Here's what happens..
Car will start straight away (even after a frosty night) but then run for about 5 minutes with the revs fluctuating from around 500 to 2000 rpm in a sort of 'hunting' fashion. After this initial glitch it then runs perfectly until...
I stop for approx 20mins. Engine is warm now but if I attempt to start it again it takes a good 2-3 minutes of cranking until it fires up. Then it'll be OK again until...
After a good long run on the open road I hit traffic. Engine heats up a little (just a notch on the temp dial from 90-100ish) but then starts idling around 2000rpm when I blip the throttle, eventually dropping down to 900 after what seems like ages. Makes city driving...er..interesting!!
What's not right here? I should add that the engines still on a 5 blade fan (I'm awaiting more funds!) so that explains the temp rise. It's a standard C3 with CIS. New fuel pump and filter. No leaks of oil, air or fuel as far as I can see.
Cheers Mark

Do a search on "hunting idle"
Probably a billion posts on this subject

Sounds like you may have several problems linked together. The idle oscilating idle usually is a sign of a too rich mixture. This may be from an out of spec WUR or an incorrect setting, which may have been done by someone to mask some air leak(s) including in your decel valve, which may account for the high idle. The high idle may also be from an improperly advancing distributor. Have you checked your points (if you have them)? Poor starting may be from a bad fuel accumulator or fuel pump check valve. As mentioned, a search will reveal a lot of info on this as this is very common in old CIS cars.