PROBLEMO solved!
its one of my leads, i mean... they're all hand made, and each have an individual coil pack (thus 4 coilpacks) but anywho one of the leads is bunged up, so we're going to make some more on Sat! (by we, im going to provide beers / pizza).
thus the lead being bunged it explains the limp sensor going off when it gets too hot, explaining why the car as i said "jolts", thus explains the backfire when fuel isnt burnt, thus explains when the car turns off, it resets the sensor and doesn't do it for about 5 seconds!! and explains why it happens randomly on and off, when ive been driving the car for ages are the times its happened, i.e. gotten too hot.
hallaluliah! im happy now.
