Volvo Penta 5.7 OSI-C not staying running

[Ohana2021]

So my engine will start for a few seconds but then it kicks out. Here is what happened and what I have done. My fuel gauge is wonky. I believe that I ran my tank dry. I added a few gallons to get back home and it ran fine. The next day it would not start. It turns over and catches but then quits. I tried to add more fuel but it kept over flowing. I cleared the gas tank vent which was absolutely clogged. Went to start again and same thing. I did turn the key 10-15 time thing to engage fuel pump to fill the fuel lines and tried to start. Same thing. I changed the fuel filter and the fuel and the filter that was on the pump looked clear. What is my next step here? It seems almost like the pump is engaged when cranking but then does not continue to pump fuel once the motor catches. Is that a thing? Can I check the pressure on the fuel pump if the motor will not stay running? This is a carbureted motor. Any help is very much appreciated.

 

[bruceb58]

With a carb'd motor, turning the key on should't turn the pump on. Did you actually hear it go on? What I would do is pull the fuel pump relay and jumper it to start the fuel pump and then try starting the engine.

The fuel pump only runs while cranking or while the alternator is outputting.

What year is your boat? It's possible thay have changed things over the years but carb'd Volvo boats should be wired with this diagram.

 

[Ohana2021]

With a carb'd motor, turning the key on should't turn the pump on. Did you actually hear it go on? What I would do is pull the fuel pump relay and jumper it to start the fuel pump and then try starting the engine.

The fuel pump only runs while cranking or while the alternator is outputting.

What year is your boat? It's possible thay have changed things over the years but carb'd Volvo boats should be wired with this diagram.

My boat is a 1998 but I think that the motor might be early 2000's. I hear something when i turn the key on. I assumed it was the fuel pump. To jump the pump am I just going to go from the battery to 87? Thanks!

 

[bruceb58]

My boat is a 1998 but I think that the motor might be early 2000's. I hear something when i turn the key on. I assumed it was the fuel pump. To jump the pump am I just going to go from the battery to 87? Thanks!

87 to 85

 

[Ohana2021]

So my motor is fuel injected. I do hear the pump when I turn the key. This is what I did today. Pulled the fuel hose from pump to tank and tested anti syphon valve and made sure lines were clear. Switched the ignition relay and the fuel pump relay and the ignition alarm and pump went on so I think the relay is fine. Checked the water line from the fuel pump to the manifold. I out the low pressure pump and the high pressure pump on a battery and they both ran. I put a jumper cable between 87 and 85 and tried to start motor. That did nothing. I put a meter on pin 30 and got no voltage. Should I have12 volts at pin 30 when the boat is off?

 

[bruceb58]

The diagram I posted is for a carb'd motor which is what I thought you had. Fuel injection is completely different.

One of the relays is for the injectors and one is for the pumps. The ECU supplies the ground to energize the relay. You do not want to use a jumper to supply 12V to the incorrect pin or you will blow the ECU output.

You will have to look online for the schematic.

 

[QBhoy]

Hi. An osi is injected.
is it kicking just as you let go of the key as it’s almost firing up ?

 

[bruceb58]

Hi. An osi is injected.

Yes but he said in his first post it had a carb.

 

[alldodge]

Might have air in the fuel rail
Connect a fuel pressure gauge to the schrader valve on the rail. With key ON does it come up between 50 to 60 psi?

Bleed at the schrader valve to see if there is any air