i was driving my cosworth the other day and everything was fine and now it seems to have developed a fault.

it seems to run very poor, stalling and the idle speed is up and down from 500 to 800 and it was originally set to 950 by myself.

any suggestions?

thanks

 

If you pick the revs up does it miss
It sounds like the Phase sencor in the dizzy mine started doing that then packed up all together found out it was all down to the phase sencor

Also a m8s cossie developed the same sort of thing started missing and check it shame again PHASE SENCOR

EASY WAY TO FIND OUT ; Remover the Dizzy cap remove the Rotor arm and plastic dust cover (if its still on there should be but some arent) and your see 2 Wires going to a half moon thingy basicly if is fcuked the wires will be bare and look all manky

Its easy to remove 2 srews and unplug the wires its abit fiddlery but not hard

Here you go Heres the link to Stu's Ebay shop this is whot it should look like (wires should be covered )
http://cgi.ebay.co.uk/Distributor-ph...QQcmdZViewItem

 

Its not your idle speed control valve sticking is it. It might need cleaning out.

 

how do you clean the idle control valve?

oh it does miss now and again and runs rough.

 

Does it do it when its warm I had mine "HUNTING" (reving up and down) which was the Idle control valve,
Disconect it and see if it idea's correctly on mine it raised the revs not dropping them
Have you cheack the Phase sensor wires as i said maybe that its a comon item to play up

 

you could also try adjusting the CO on the ecu

 

check the distributor phase sensor or its possibly a dead plug