15 replies to this topic

[Mini Man Dan]

This is yet another cry for HELP! My mini is driving me up the wall now! My engine after being rebuilt (twice dry.gif ) is still causing me problems!

as far as I can remember everything is new or reconditioned.

Recently had new plugs, leads and dizzy cap, yet it still only runs on 3 cylinders! I have just done a compression test and got 120 on number 1, 125 on number 2,3 and 4.

The mixture and timing have been set up twice by a mechanic I know and still got the damn problem.

The plugs are oiling up rather quickly aswell (not helped by short journeys)

Any ideas as what I can try next before it pushes me too far and I sell the little censored.gif

Thank you
Dan

[minimender]

Do you know which cylinder isn't firing or is it random?
Could be rich mix, does it run without choke when cold, could be leaving choke out too long and fouling plugs.
Try new rotor arm and condensor.
out of ideas

[blacktulip]

ID the problem plug by trial and error taking it in turns to take one ht lead off. is it oily plugs or fuel? make sure the choke mechanism isnt stuck or try adjusting the mixture down again.

Edited by mikecmini, 21 February 2008 - 08:58 PM.

[Mini Man Dan]

Its Number 3 cylinder thats not working
Its had new points and condenser and rotor arm

EDIT: No it doesn't run when its cold if the choke is in

Edited by Mini Man Dan, 21 February 2008 - 08:59 PM.

[minimender]

Swap the No 3 plug with another one.
Check dizzy cap, even if new it may have a crack in it. Swap it for the old one for the process of elimination.
Check rocker arms and tappet clearance on No 3out of ideas again

[Mini Man Dan]

Swap the No 3 plug with another one.
Check dizzy cap, even if new it may have a crack in it. Swap it for the old one for the process of elimination.
Check rocker arms and tappet clearance on No 3out of ideas again

The old dizzy cap is broken

Its a new plug and had the same problem before the plugs were swapped.

Rocker clearance have all been checked

[minimender]

Cant be valves if compressions good so if rockers are working then it must be electrical.

If you havent had the carb off it wont be a dodgy gasket part blocking the inlet or exhaust (which I have done before)

If No 3 is getting a spark then it will be fuel, timing or mechanical that is preventing the firing.

If timing and fuel are correct then it could be mechanical.

Compression test rules out a cracked valve

Valves may not be opening correctly

out of ideas again

[Mini Man Dan]

Cant be valves if compressions good so if rockers are working then it must be electrical.

If you havent had the carb off it wont be a dodgy gasket part blocking the inlet or exhaust (which I have done before)

If No 3 is getting a spark then it will be fuel, timing or mechanical that is preventing the firing.

If timing and fuel are correct then it could be mechanical.

Compression test rules out a cracked valve

Valves may not be opening correctly

out of ideas again

Will go and set the rocker clearances again. There is definately a spark and definately got fuel going to it.

All the plugs seem to be a bit black

[minimender]

Could be timing retarded a bit and not burning fuel correctly, not all mechanics know how to set timing and need a book or figures to go on and its not always correct if done from a chart or maual.
Or..... vac advance may be iffy.

Tappets can't be that far out or compressions would be down ... unless one of them is too wide , but then you would hear it ?

Would love to get my hands on it for half an hour ..........  grin_with_flash.gif   1.54K   1 downloads

[digitalboy0]

if spark plugs are black its running to rich which is more fuel not enough air just try setting mixture if not

get the hammer out always works ! if hammer dont solve it its electrical im afraid lol

[minimender]

If spark plugs black then its not burning all the fuel its getting, either because too much fuel or inefficient burning in cylinder which could be weak sparks or timing or both. But if rich then it would run ok when cold without the choke so I'm thinking needs advancing. You cant have too much advance as long as it dont pink.

[Mini Man Dan]

Would love to get my hands on it for half an hour ..........  grin_with_flash.gif   1.54K   1 downloads

Feel free! Will give you a crate of beer if you can fix it

[minimender]

Just eliminate one thing at a time and you will end up at the problem.

My money is on errrrrrrrrrrr.
Tappet
Broken/leaking inlet manifold
Water /Damp in ign somewhere

Need to know now

[Mini Man Dan]

Just eliminate one thing at a time and you will end up at the problem.

My money is on errrrrrrrrrrr.
Tappet
Broken/leaking inlet manifold
Water /Damp in ign somewhere

Need to know now

Can rule out the water/damp on ign somewhere as it not that.

Not checked for a leak on the inlet manifold! Thats the next thing to check in the morning. Tappets already checked.

[minimender]

Best of luck with it then, be sure and post up what the problem is.

I'm off to the lake district for the weekend tomorrow for....  Guiness_pint.gif   9.76K   1 downloads then...  lets_do_it_wild.gif   3.13K   1 downloadsand maybe...  pissed.gif   13.76K   1 downloads