No fuel at start

[HoytAdickes]

First boat here so please excuse my ignorance. I am decently mechanically inclined though with cars. Not the same I know.
So I have a 2005 volvo penta 4.3 GLD engine. Bought boat used last season, and it did ok. Few issues but nothing big. Winterized it, and just getting it out to unwinterize. Replaced starter, filters, oil, plugs, wires, cap and rotor. I did fill fuel filter when replaced. Boat will not start without pouring fuel into carb. It will start when I pour fuel into carb, and run until I shut it off. I can even increase rpms in neutral no problem. I have checked fuel system using the sticky in adults only section. Power to relay, no blown fuses, power to pump when it's running.

I'm at a loss please help a newbie out please

 

[HoytAdickes]

I should also add that if I run a jumper wire from battery straight to pump the pump will run, but when I turn ignition key forward I cannot hear it run.

 

[HoytAdickes]

Ran a jumper wire straight from battery to pump this morning. Pump kicked on and stayed running. However, boat still won't start.

I'm going to try to find a relay locally and maybe a pump. I could really use some help

 

[Scott Danforth]

first, welcome aboard

next, slow down, some of us need coffee

third, have you traced the wiring back to the fuel pump with the factory wiring diagram in the manual?

if not, start there. check the diode and the fuel pump relay feed from the start circuit. then check the safety from the oil pressure switch.

 

[HoytAdickes]

first, welcome aboard

next, slow down, some of us need coffee

third, have you traced the wiring back to the fuel pump with the factory wiring diagram in the manual?

if not, start there. check the diode and the fuel pump relay feed from the start circuit. then check the safety from the oil pressure switch.

Safety from oil pressure switch? I can tell you my oil pressure Guage had never worked since I bought the boat. No issues at all last year. Seems the issues started when I replaced the starter

 

[Scott Danforth]

Then get the manual and make sure the wiring is correct

And yes, your fuel pump should be wired the the start circuit and an oil pressure safety switch. Power comes from a diode near the alternator

 

[HoytAdickes]

Then get the manual and make sure the wiring is correct

And yes, your fuel pump should be wired the the start circuit and an oil pressure safety switch. Power comes from a diode near the alternator

I just can't figure out why it will start and stay running when I pour gas in carb, but when I jumper wire straight to pump it will not start at all. Makes zero sense to me.

Starter wiring is correct. Used diagram to double check. I have downloaded manual, and it isn't much help. Guess I need a shop.

 

[Scott Danforth]

It runs wgen you hot wire the pump directly

It dies not run when you go to the relay

Check the oil pressure safety switch, check the diode.

 

[HoytAdickes]

It runs wgen you hot wire the pump directly

It dies not run when you go to the relay

Check the oil pressure safety switch, check the diode.

It will not start when I hot wire the pump. I can hear pump running, but it will not start the engine. Only way to start the engine is pour gas into the carb. Then it'll start right up, and run forever until I shut it off.

I'll look into oil pressure switch I guess, but I'm lost. Thank you

 

[alldodge]

Seems the issues started when I replaced the starter ​

The fuel pump is turned on by the Yellow/Red wire thru a diode to the FP relay. The same wire also energizes the starter relay which cranks the motor. Once the motor is running, power stops on the Yellow/Red and comes from the Green wire thru another diode to the FP relay.

Note the wires on the starter in the pic below. There is a purple wire on one terminal of the starter and Yellow/Red on the other

 

[HoytAdickes]

The fuel pump is turned on by the Yellow/Red wire thru a diode to the FP relay. The same wire also energizes the starter relay which cranks the motor. Once the motor is running, power stops on the Yellow/Red and comes from the Green wire thru another diode to the FP relay.

Note the wires on the starter in the pic below. There is a purple wire on one terminal of the starter and Yellow/Red on the other

That is how my starter is wired. Yellow/red goes to the 3 o'clock. Purple to the 9 o'clock. 6 is starter motor only, and 12 is three power wires.

I used a diagram off these forums to check, double check, and triple check the wiring

 

[Scott Danforth]

dont go off positions, go off labels. not all starters have the terminals in the same location.

the B terminal goes to battery (big red wire)
the S terminal goes to the start pilot relay (yellow wire with red stripe)
the I terminal is wired to the alternaor, coil +, etc (purple wire)

 

[HoytAdickes]

Oil pressure switch connection is rusted pretty bad. I'm gonna clean that up. I don't see how that would cause it not to start if it's supposed to bypass that upon cranking anyway though.

 

[alldodge]

On the GL model the oil pressure switch just sounds an alarm, same as exhaust overheat and water temp overheat

My point on the wiring is you just replaced the starter and then you had no fuel pump, and now no spark, so there is a wiring issue. A connection is loose or corroded

 

[HoytAdickes]

On the GL model the oil pressure switch just sounds an alarm, same as exhaust overheat and water temp overheat

My point on the wiring is you just replaced the starter and then you had no fuel pump, and now no spark, so there is a wiring issue. A connection is loose or corroded

I have spark all day long. If I pour gas in the carb it'll start right up. Just won't start without pouring gas into carb. That's where I'm at. If I straight wire pump it will run, but won't start

 

[HoytAdickes]

Replaced relay..... No fix. Poured gas in carb. Started immediately

 

[HoytAdickes]

On the GL model the oil pressure switch just sounds an alarm, same as exhaust overheat and water temp overheat

My point on the wiring is you just replaced the starter and then you had no fuel pump, and now no spark, so there is a wiring issue. A connection is loose or corroded

OK so I removed, and reinstalled starter. Wiring is correct both times on it. Still will not start. Just cranks all day. I removed fuel line coming from my single fuel pump at front of engine. The line that goes directly into carb. When cranking engine over fuel comes out of that line no problem. Yet still will not start. I pour gas into butterfly of carb..... Starts right up and stays running.

 

[HoytAdickes]

Had an assistant pump throttle (in neutral) while I held butterfly to carb open looking down with flashlight. I saw no fuel shooting into carb. I poured fuel into carb , and it started right up. Again lightly pumped throttle while I looked down.... Still see no fuel shooting in, but it stays running.

I'm baffled

​

 

[Scott Danforth]

look at your carb too. if you have no fuel squirting, you have no fuel in the bowl.

since your fuel pump is squirting fuel, check your fuel pump pressure. it should be 4-7 psi. however your float could be messed up. should be a holley 2-barrel. about the easiest carb in the world to work on. one touch simpler than a kohler toilet.

my guess is you have crud in the bowl plugging up the accelerator pump circuit.

 

[alldodge]

my guess is you have crud in the bowl plugging up the accelerator pump circuit. ​

Agree, need a carb rebuild