right stick with me on this as need some opinoins
right tonight ive been trying to figure out what wrong with the car and whats causing it to missfire, i did the following by a process of elimination.
right first up, pull out plugs, 1-2-3 were all black and sooty, no4 was completely clean, almost as if it hasnt fired since i put the engine back in, so then looked down at the crowns, 1-2-3 were a bit sooty, no 4 was completly clean.
Ok next, i pulled out the injectors, and while still on the rail i pointed the upwards and cranked over the engine, every one was spraying fuel, but i had a spare set and swapped the over and they were the same too, all firing together, next i put the plugs back in and got it running, pulled the wiring clip of injector no4, no change on engine running, put it back and then did no 3, engine promtly died, so swapped the wires round on 3&4 and it started fine, and it was the same again, pulled of 4, no change, pulled off 3 engine died.
next, got engine running again pulled the HT of no 4 from the dispack no engine change but the was a spark jumping from the pack to the lead, put it back on the pack then did the same to the plug end, pulled it off, and the spark was jumping to the plug and the bore untill i removed it, then got it close to the engine again and it was sparking away, pulled of lead no 3 and the engine died, i had a spare lead in the garage so used this on no 4 and it was still the same.
ok, running out of ideas, so i have a hunt for an old plug, pull out no4 and put the plug in the end, crank over and its sparking, so i put this pulg in the engine and it sound to run everso slightly better, hmm, odd pul off the lead on no4 and it sound a little bit different and then put the the origonal plug in the lead and earth it out and it sparks.
now im completely stumped, it sparks out of the engine but when its in its not firing atall, could it be tha it breaking down and firing when it feels like it, or is it that the compression has been upped and is blowing out the spark(they are all gapped at 0.8mm).
or could it be the dispack that is faulty, i dont know the history of it as i got it second hand.
also i used an exhuat gas analyzer and it reading between 1.5%-1.8% CO2 at idle.