hi just moved back to uk from nz, sold my mint 4x4 over there and now i have a less than mint 4x4 with a huge misfire, rev counter flaps around and reads about double slight misfire felt around 2500 rpm more notacible out of gear or in low gears then runs fine until 5-5.5k rpm when engine cuts out and back fires, again worse in first and second.
i have tried two sets of plugs with gaps from .5 to .7 champion and bosch iridiums, leads, group a coil, cps gap 0.6mm phase sensor gap 0.2mm checked conections on both sensors there are no air leaks and the problem is the same at 22psi and 15 psi so it is not overboost.
i have spent three days looking at old posts and am now at loose end any help please,,,,, kev

 

Welcome back

And to Pf too

Is the cps wiring all ok ?

 

thanks all looks good and no high resistance across multiplug i have tried the air gap at 1 mm 0.7 mm and 0.5 mm to no avail

 

hi mate sounds like the same thing happened to me maybe not a misfire but a boost problem check the terminals on the amal valve give it a good clean sorted my problem

 

Try disconnecting your rev counter/clocks and trying it.
tabetha

 

Does the missfire occur in conjunction with the rev clock going haywire?
the cozzy rev clock is known to go a bit mad now and again, sometimes often spiking 7000 rpm when only doing 3000.
and the odd time a missfire can happen at the same time.had a problem like that a good while ago as well as several others on here.
the problem is appears to be earths, or more specifically the earth on the inlet manifold and or bad joints at the multy plug connections at the bulkhead.
that would be the first route to go, and see how you get on

 

velocity your a legend found oil from breather tank had run down into multiplug, cleaned it out and now runs like a dream, thanks for your help everyone.