i kept the ecm but I have HEI ignition. the pump comes on the the few seconds initially then shuts off like normal, but onces the motors fires up it wont kick on. I have a working signal from my oil pressure gauge but cant find the right wire for my tach signal to the gauge.
on the harness for the old 4.3 distributor I had 3 wires. with the key on I have
Black/red - ground
Red + lower voltage around 10.5ish
Black/White which I get no ground or positive voltage from
I hooked the tach signal from my HEI to the black/white but still got nothing
If i have to i will just put in an aftermarket tachometer but i still dont know if the tach signals the fuel pump relay to turn on
At the HEI with the key on I am getting around 10.5 volts NOT running is this normal??