what causes breakup? maybe not the right term for this...
 

ok, under low load everythings cool, but under wot or a little less my car will (seemingly randomly) jerk and it feels like there is breakup in the power band.

its really noticable and really anoyying, its like all power dies for a half second an i slammed the breakes then its back to normal for another 600 rpms.

its almost like detonation, but only under wot.
what do you think? timing? ive been working on that with a friend to no avail. what else could it be?

fouled plugs or worn out plug wires would be my best guess.

your T2 fuel pump is also too much for an n/a engine unless you have a way to lean out the mixtures. personally there is no reason for that pump unless you have done some serious n/a mods like massive porting.

better grounds might help as well?