Cylinder 2 problems

[Al1exx]

Hi everyone,

I'm having trouble with cylinder 2 on my car, it doesn't seem to fire, and was hoping someone could point me in the right direction. My mini hasn't really run correctly since I got it, and I've replaced a few parts as I've gone along and managed to get an MOT. As I use it for work just now I can't really put it off the road which is a bit unfortunate. I've replaced the leads, plugs, dizzy cap, rotor arm.

Fault - cylinder 2, (in case I'm describing wrong, I mean the cylinder 2nd along from the radiator) never seems to fire. Can feel the misfire at the exhaust. Hot cold, at speed or at idle it never feels like it is firing though the plug is sooty so it must fire sometimes? But definitely not at idle. Car otherwise runs very strong and drives well.

I identified the fault by pulling the lead when the car was idling, no change in tickover - can hear a crack-crack-crack from the lead when held near the plug so it is getting a spark. Plug is sooty but not damp & other plugs appear normal. Mixture correct (lift pin test), swapped plugs and leads around, problem remains in cylinder 2. Fault was evident before and after new parts fitted - new parts were fitted as car was impossible to start one day and I found the cap was damaged. Removed pancake filter for a short time in case it was badly blocked, made the car run slightly better (so I'm putting normal airbox back on!) , but didn't help the cylinder fire. No trace of sparking off the leads to the block etc in the dark either. Could a faulty earth cause only 1 cylinder to go?

Was thinking next port of call, valve clearances, compression test? I didn't think it was the coil, points, or condenser as it's only 1 cylinder and the fault never moves or changes hot or cold? Also, what damage could I be doing driving the car with only 3 cylinders?

My car is a 998 cc, standard as far as I can tell, 1986 vintage - any pointers would be great!

[nightrain]

Valve clearances need checking this is the most likely cause especially as you've done everything else.

This is something that I can never understand, checking and adjusting the valve clearances is FREE. Provided you've got the tools, so why is it nearly always the last thing people check ! When it should be one of the first.......

Not having a go at you personally Al1exx, just half my posts seem to start by asking the same question...........

[Al1exx]

Thanks very much for your mate,

I replaced those parts because the day after the MOT the car wouldn't start, and these parts seem to have fixed that issue - though I did hope they'd fix the misfire too. The other fixes I've tried (swapping about parts, taking off the airfilter etc.) were free - I agree free is always the way to go first & chucking a fortune at the car to find it needed a free fix would be a bit gutting!

Just wanted to check I'm on the right path as I'm new to mini's, thanks for confirming

Will report my findings back!!

[philster]

as above check the valve clearances on no.2, if they are okay then a compression test would be my next port of call

[MINIPETE]

I identified the fault by pulling the lead when the car was idling, no change in tickover - can hear a crack-crack-crack from the lead when held near the plug so it is getting a spark

I'm sure I'm missing something and you've covered this, but is that particular plug actually creating a spark? I've replaced a set of plugs before and had a couple go within weeks, mentioning no names 'cough' NGK 'cough'!

[Al1exx]

Thanks for your reply mate, I swapped the plugs around and the fault never moved so reckon the plugs are all okay

[MINIPETE]

No worries - thought you'd have it covered but anythings worth a try sometimes! I've been in the situation in the past where you replace one thing then something else goes and so on! I'll hand you back to the experts....