Misfire on idle

[James Q]

Hey guys/girls have a misfire on idle on my 1.6 webber carbed driver ('91) drives beautifuly still no misfires during driving etc only when the cars idling hot or cold, any ideas before i start changing every thing lol? Havn't tried anything as yet, the throttle is responsive, and theres no smoke on start up, hard accelerating etc.

[mk2bal]

Well if it isn't plugs,leads, dizzy cap or rotor arm then it'll be the carb needing tinkering with as the idle part and running part are different and can behave differently if not set up right. Try pulling plugs out and checking they all spark, then you can dismiss them and the ignition side of things from the equation

[Santiago]

Check the thick rubber vac hose that comes off the inlet mani towards the hard plastic brake servo hose via non-return valve.
Can crack/split on the underside out of sight.  Air leak there will lean out the mixture (mostly to pot 4), potentially causing missfires, especially at idle with lots of vacuum in the mani.

[James Q]

will see what i can do, if its this, where can i get a replacment hose from and is it just a case of swap one for the other or is it more involved then that?