Electric fuel pump on 4.3L OMC

[illini]

I have a 4.3L OMC with an electric pump that is not coming on. I disconnected it an jumpered 12v to it and it works fine. I need to know if it should come on with the key in the on position or does something else cause it to come on? Does it run continuously with the motor running? If it does could I just wire it to a hot lead the is supplied from the ignition switch? If I fill the carb bowl by jumping the pump the engine runs fine until the bowls are empty. What is a good source for elec wiring diagrams for this boat/eng? It is a 1990 19ft seaswirl.

 

[McKenzie]

Re: Electric fuel pump on 4.3L OMC

As i see it in my clymer manual, the fuel pump is controlled by a relay that works off of the alternator and ignition circuits, plus a few diodes and breakers. Also looks like the starting circuit could be involved. Good Luck!<br /> Page 331 Clymer OMC

 

[denniz]

Re: Electric fuel pump on 4.3L OMC

Works only while cranking off the starter solenoid. (purple wire)Until it starts then it should run off the alternator. Green wire if i remember correctly.

 

[illini]

Re: Electric fuel pump on 4.3L OMC

I appreciate the advise. I will check it out tommorrow. With any kind of luck I can trace the wires. It helps knowing what to look for. I also heard that the pump cycles. Is that true? It's hot here in San Antonio and I want to get back in the water.

 

[akriverrat]

Re: Electric fuel pump on 4.3L OMC

pump runs continually when engine running. uscg regs require that the the pump will not continue to run with engine stopped. however the regs do allow a momentary on switch to be wired into the circuit for the purpose of priming the carb. if the engine quit because of broken fuel line after the pump it could get very ugly if the pump continued to run. BTW most electric pumps are controled by an oil pressure activated switch.