83 non-start

[jeremy kammerer]

my beloved 244 quit from one beat to the next, a few miles after turning 390k, with no warning except a half-dozen momentary stumbles at low rpm in the couple previous weeks. My capable friend has found: pin check reveals no broken wires or wrong voltages except idle microswitch and idle adjust screw. Problem is that the grounds which the brain switches (fuel pump relay, system relay, and injectors) are not being switched. Battery and igniton-switch voltage seems to be everywhere it should be, and there is a cranking signal.
We're no longer sure of the cpu that was in it or the spare that worked when I bought it from the yard. There is some lore about the possibility of burning out the cpu with improper voltages from somewhere in the system, but we have no detail on that. We're going to try to find a shop here that has a working '83 and would use it to see if the cpu's work.