Idle speed too high

[RickyJ]

Hi Everyone - I have my VX in for an MOT Retest this week and the last thing on my list of things to do is the emissions.

It failed originally as the garage couldn't do the emissions test as it was idling too high (around 1800rpm). I'd set it to this speed with the idle stop screw as it wouldn't idle any lower without cutting out. Does this sound like it could just be poor idle mixture settings? The car backfires when you turn it off but other than that it runs normally, no spitting/popping e.t.c. so does this suggest it's running too rich?

Any thoughts/ideas Gratefully accepted!

[A1.6HPE]

Is the idle jet cut off solenoid valve working OK ?
Check that when you turn on the ignition the solenoid on the side of the carburettor clicks - you proably need an assistant to do this. Alternatively turn on the ignition and disconnect and reconnect the feed wire. This is assuming that the VX carburettor has such a thing, but I believe that it has. If not working the idel jet would not get a supply of petrol. Other possibility is that the main choke idle jet is blocked by dirt.