Lindsay123
16th November 2014, 04:32 PM
Hi guys,
I've got a missfire on my '94 model v8 disco, it's on straight petrol.
All leads are definitely sparking as i've had them off to check, however cylinders 5 and 7 aren't firing properly. Haven't checked the compression on them as i don't have a compression tester. Gets worse under load as you would imagine. but it is present at idle.
I took the plugs out, 5 and 7 are pretty black but the rest are fine... one of my mates suggested a possible crack somewhere in the back of the intake manifold, obviously this would be a last resort, i can't find any threads relating to the same issue so any suggestions would be great!
What i did to work out it was 5 and 7 misfiring: started engine up, took leads off the dissy one by one, 5 and 7 made a difference in running, the rest didn't make a difference to the idle... hopefully i did this correctly??
I'll be replacing, plugs and leads this week, would it be worth replacing the coil if these don't fix it... or would that be a pointless thing to do?
thanks in advance guys :)
I've got a missfire on my '94 model v8 disco, it's on straight petrol.
All leads are definitely sparking as i've had them off to check, however cylinders 5 and 7 aren't firing properly. Haven't checked the compression on them as i don't have a compression tester. Gets worse under load as you would imagine. but it is present at idle.
I took the plugs out, 5 and 7 are pretty black but the rest are fine... one of my mates suggested a possible crack somewhere in the back of the intake manifold, obviously this would be a last resort, i can't find any threads relating to the same issue so any suggestions would be great!
What i did to work out it was 5 and 7 misfiring: started engine up, took leads off the dissy one by one, 5 and 7 made a difference in running, the rest didn't make a difference to the idle... hopefully i did this correctly??
I'll be replacing, plugs and leads this week, would it be worth replacing the coil if these don't fix it... or would that be a pointless thing to do?
thanks in advance guys :)