I'm sorry for the constant posts in here but i'm gettin nowhere with this car so giving it one more try in here then i'm thinkin of breakin it:

its a 1992 j plate 4x4 cossie with green top engine, full stainless and prev owner advised it had been chipped (stage 1) - one day it just refused to start and a friend of mine who is good with cossie thought it was electrical, i replaced all engine bay sensors with new ones from matt lewis motorsport, ignition amp and wiring has been replaced for new ones, fuel pump and filter been replaced with new ones, new plugs and leads, dizzy cap and rotary arm replaced also. After all this was replaced the car started and ran perfect, best its ever ran! then a couple days later it started missing and was like it was blowing out the spark higher up the revs. after it did that it would start and run great till it blew out the spark again. its gotten worse and now it barely starts and when you try and rev it, she coughs and die and backfires!! any ideas?

 

Have you looked at the CPS connector, does it belch black soot out whilst running bad, what colour are the plugs, what chip is it(make), have you checked CO, had it on the rollers ?
tabetha

 

did u get the plugs from matt lewis & were they 071's?
looks like he's had a bad batch of them lately as a few people on here have had similar symtoms with brand new plugs

 

i did mate aye, 071's from Ford.....car just never been right since?

 

try another set of plugs either ngk bcr8es or champion qc59c.
or if u feel like spending- some denso iridium ones.