missfire under boost

[markey b]

strange one, have an occasional missfire on the orange car under boost, usually above 20psi, it stutters and pops under load

i've got an MSD coil so should be strong enough, and iridium plugs as the OE ones i had used to do it worse

almost like its blowing the spark out?!?!

i have got to change dizzy cap and rotor as the new coil may have eaten them, but i've only done a thousand miles on them iirc

anything i should look out for apart from the obvious dizzy cap and arm?

[James5]

You sure it's not a fueling / det issue

[Brigsy]

If all the ignition components are good, try gapping the plugs to .5mm. I used to get the occasional bang/pop on boost and this cured it on mine.

[markey b]

You sure it's not a fueling / det issue

no 'tinkling' noise and AFR's are good, mike48 set it up for 27psi and i've only gone up to 20 since the last build lol

i'll try gapping plugs and try them again, if not i'll see if i can get fuelling fiddled with :cartman:

[markey b]

just an update so that the 'search' function may help out others..

got the car out for first time since last post in this thread, checked gaps...

one plug was over a mm, now all set to 0.5mm and its perfect, no missfires

thanks rtoc :agree:

[Eugein Offord]

aei pipe from carb ... ...........................