When my 3 door cossie is ticking over,it's misfiring on back cyldner.but when driven is running fine,tried leads and plugs but still the same.if there is anyone out there with answers to this please get on to me.
My email is johnnymac2@hotmail.com
Anyhelp would be very appericative.
Thanks John

 

Hi Mate,
if you are sure the plugs and leads are ok then it could be an air leak into the manifold, test this by spraying a sniff of easy start around the intake manifold, if the engine picks up then a new gasket is needed.

If this does'nt work then you could possibly have an injector (not delivering enough fuel on tickover) or a wiring problem. The other possibility is that you could be losing compression so best carry out a compression check and see what the readings are across 4 cylinders.

Hope this helps!

Regards, Mike.

 

could be the head gasket letting water in on idle, then as the revs rise the cylinder pressure keeps the water out. i have had this in the past.