I recently sank my 85 pickup and fried the ecu. i picked up a new one for it and plugged it in just sitting on the floor. every thing seemed fine for a couple of weeks and i even drove it around the block a few times. the other day i drove a few miles down the road to a little wheeling spot and made it about 200 yards down the trail before my truck died and would'nt start again, its acting just like it did when i fried the old ecu. it will run off starting fluid so i know its not an ignition problem. i guess the fuel pump could have went, havn't check that yet. i didn't get any water in the fuel tank.

Does the ecu need to be grounded? because this one wasn't, unless its grounded through the wiring carness. any other ideas?

I will answer any q's as best i can. thanks