Idle/Starting Don S. Please Help!

[TheFatKid4]

Volvo Penta 5.7 Osi-DF

Let me start in the beginning. Saturday I took the boat out for the weekend. I ran the boat for 45 minutes and anchored in a cove for the night. After 5 hours at rest I went to start the engine to charge the batteries. The engine would not start. Sometimes it would kick over but only by throttling up could I keep it running. When I placed it back to its regular idle it would shut down. After a bunch of tries at this I stopped trying. I took the key out of the ignition, turned the batteries to off and turned on my external portable generator.

The next morning, Sunday, I shut the generator off, turned the batteries back on and started the engine. It started fine, with no hesitation, like always. I drove back to port. The engine ran great at all speeds. After docking I shut down the engine and waited. After a half hour I tried to start the engine it acted just like it did the day before. It would come up to idle and shut down, come up to idle and shut down. Now I hooked up the shore power turned the batteries off and left the boat.

On Monday morning I started the engine and it was fine. I take another long ride, the engine was running great at all speeds, come back to the dock and shut off the engine. I waited 30 minutes and tried to start the engine only for it to come up to idle and shut down just like the days prior.

UPDATE:

As of Thursday, no more short rides, the engine will not stay at idle. It cranks over smooth, starts smooth and then shuts right down.

Please help me figure out what?s going on!

FYI- 2004 Throttle Body GM Multi-Point Fuel Injected

 

[rangoneer]

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

Starting from the beginning, it seems as though the batteries got drained and now the alternator can't build the batteries back up to cranking power.

Question: when you take your 'long run' and shut off the motor, what accessories are you running and how long are they running before you try to start it up again? CD player? do you leave a fish finder or depth gauge on? Anchor/navigation lights/courtesy running lights on?

Perhaps when you are at the dock and you charge the batteries up. Wait the same amount of time you do when on the water before starting up and see if that replicates the situation. At this point, it seems like battery issues or the charging system (alternator).

I'm sure someone that knows for sure will chime in.

 

[TheFatKid4]

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

The batteries and alternator are all operating at their respectable volts and amps. The engine starts but shuts right back off.


UPDATE:

As of Thursday, the engine will not stay at idle. It cranks over smooth, starts smooth and then shuts right down.

 

[TheFatKid4]

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

Don S. Please help me!!!

 

[JustJason]

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

I'm not Don S. but I can tell you if unless you have at bare minimum a techmate scan tool, a digital multimeter, and the correct manuals, your not going to fix this motor. So do ya have a scan tool and multimeter?

 

[Don S]

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

Re: Volvo Penta 5.7 Osi-DF Idle/Starting

The first thing I would be doing is some fuel pump pressure tests on both pumps to make sure they are coming on and working when they should.
It could be as simple as a corroded relay, or loose wire.
Post a SN for your engine, and I can find what manuals you need.

 

[jtybt]

Re: Idle/Starting Don S. Please Help!

Is it shutting down as soon as you let the key off the 'start' position?