ok i have a similar prob with mine, if im cranking it drops voltage to the computer, try wiring the computer straight to the battery with a fuse of course. I have to tease my ign so its just cranking otherwise it wont start. i.e just on the verge of cranking otherwise if i turn the key too far it will just wind over and over infintum. its something to do with having batt in the boot. when i had the computer with power all th tim it would start no worries. for a while i had a it hardwired to batt and had a switch on it. try that anyway