Hello, Just learned about this great site while doing research in a '67 Chrysler I found for sale. (original owner, 105 HP all records)
Anyway, I am trying to help my son diagnose a problem he has on his V/P 7.4 EFI engine. The lift pump recently failed and it has been replaced. We have attempted to diagnose the inability to start and have found that she will start and run if we provide voltage to the relays (switch side) that provide power to both fuel pumps. The purple wire has power but the green/white wire leading from the ECM (pin # 9) to one of the relays does not have voltage and that is as far as we have gotten. All else appears to be fine. We did check the oil pressure switch as we learned that failure to build pressure apparently may be a potential caue. Relays test out fine, just a no (switch) voltage issue at one of them. Any help or direction would be much appreciated.
Anyway, I am trying to help my son diagnose a problem he has on his V/P 7.4 EFI engine. The lift pump recently failed and it has been replaced. We have attempted to diagnose the inability to start and have found that she will start and run if we provide voltage to the relays (switch side) that provide power to both fuel pumps. The purple wire has power but the green/white wire leading from the ECM (pin # 9) to one of the relays does not have voltage and that is as far as we have gotten. All else appears to be fine. We did check the oil pressure switch as we learned that failure to build pressure apparently may be a potential caue. Relays test out fine, just a no (switch) voltage issue at one of them. Any help or direction would be much appreciated.
