thanks for that mate. just kinda tested the coils out by starting the engine and lifting each coil out to see if it was sparking.
looking at the front of the car it was the 2nd in from the left that i thought had gone as i did this test and this was the only one not sparking and once replaced it then idled fine. so i replaced it with a brand new one tonite
then i took it out for a drive and anything over 7psi it runs on 3 cylinders.
so i did the test again. the coil furthest left was sparking intermittently then stopping then starting then stopping etc. and when i put it back on the car the car idled smooth again. did the same with the one i just replaced (£30) and this one didnt have a spark at all? the next two did (the one on the far right and the one next to it)
i dont understand... surely there would be an intermittent regular spark pattern on all? the only one that i would say may be faulty is the one on the far left that sparks then stops then sparks again.
what would you say?