Is fuel pump supposed to run entire time engine does?

[jamesdgreen2016]

I have a mercruiser 4.3l from 1993. It has an electric fuel pump added. My mechanic told me it is supposed to run or make noise like its on the entire time the motor is running then shut off when motor is off. And turn on when you turn the key to prime the engine. Is this the case?

 

[harleyman1975]

It should be running the entire time engine is running. It is only producing about 4-7 psi.

 

[R055]

It runs when the ignition is on and the is oil pressure.

 

[fhhuber]

Should be wired to go on with ignition.
It should be running when the starter is cranking. (some ignition switches may cut off certain accessories when starter is cranking, to use max power for starting the engine)

Since you seem to indicate its an aftermarket alteration, there are plenty of ways the wiring could have been done wrong... and one way that is correct.

 

[jamesdgreen2016]

It was replaced at marina last summer. It turns on when ignition is on, and stays on the whole time the engine is running. I have no reason to believe it has a problem just that someone mentioned it to me and i wanted to make sure it is supposed to do all that. Which it sounds like is the case.

 

[Bt Doctur]

Simply turning the ign on should not run the electric fuel pump.
Wired to the starter solenoid it energizes the pump during the cranking phase and then once oil pressure is reached it switches over to the ign feed

 

[Bondo]

I have no reason to believe it has a problem just that someone mentioned it to me and i wanted to make sure it is supposed to do all that. Which it sounds like is the case.

Nope,.... Not the case at all, it's wired wrong,.... No oil pressure switch by-pass,... a Safety Issue,....

 

[josh_booth]

Per my Mercruiser dealer, electric pumps must be wired through the oil pressure switch. Just think the danger of having a fuel line break and your electric pump dumping raw gas into the engine compartment.