Hey mate, I have a bj73 cruiser, had a similar issue only a few weeks ago, drove me mad, it'd start fine, run for a while, id get to say a roundabout or intersection then it'd just die, blow the engine fues, id replace, drive again for no spacific amount of time and it would happen again, It took about 4 fues before i relised it was everytime i hit my indicator (well, 2 secconds after), turned out to be the indicator globe was smashed inside the housing and the ligh filiment was touching the body
Hope that helps
Grant
Bj73: 8" lift -> 12HT Motor from a HJ61 -> 35" Cooper Stt's and a heap more