2 replies to this topic

[ducatibip916]

hi, first ever post so be gentle, help to cure a missfire

just rebuilt my 1990 mini cooper engine with  new pistons/ rings to 1293cc ,45 dcoe medium length race manifold  with modified bulkhead ,kent high lift cam 286, with adjustable vernier ,new coil . aldon distributor, race with no vac.new leads ,plugs  ,ported big valve head , race fuel tank with fuel reg ,surge tank, and twin fuel pumps

my problem is on cylinder 1 and 4 when you remove the plug leads  it makes no difference ,carried out a compression test and these are 180 psi   . 3 and 4  200psi, carried out a leak check  no real loss any cylinder, spark ok,

please help !! 

 

[Rob7620]

Have you tried swapping them or trying new leads and plugs?

[nicklouse]

is the miss at all times or just tickover?

 

i would expect higher compression readings for a fresh engine as well.