i have a missfire in my stage3 4x4 only when on full boost i have check the gaps on plug thay r ok it as had new leads,distributor cap,phase sensor&rotor arm.i have had a new cambelt fitterd could this have anythink to do with it thank

 

have you replaced the plugs and what plugs are in there at the minute??

 

check the connectors above at the back of the engine. give the connectors a good clean and tight them real good. trough the years the inside of the connectors will get a little bit wider.

 

Have you tried another coil?How much boost?Check fuel pressure.

Roger

 

what leads are you running i had this problem on blue motorsport leads put a new set of standard buru ones on and missfire gone

 

 

a 2.5year old topic...

 

It sounds very much like it is blowing the spark out at high boost.
THIS IS NORMAL, as ford fitted such crappy coils to them as STANDARD, ie the only good place for it is the bin.
I used 909 leads and they caused running problems, so switched to MAGNECOR, massive difference much better.
I then was still not happy as it had a few misfires when cold so on went a GROUP A coil, this sorted it.
It also improved bottom end response enromously ran smoother all the time, and is the bset £32 I ever spent.
These firt dstraight on once you have replaced connectors on the ends of the (LT) wires as they use spade connectors and not the round one on the oe coil.
What gaps are you running ?, 0.6mm works best on std coil, you can open gaps up on group a coil as it is not weedy like the original one.
tabetha
ps timing belt has nothing to do with this