Volvo Penta starts but dies quickly

[hoitoto]

Need help! My Volvo Penta starts but dies quickly. Here's the background:
During winter, boat cover mal-fundtioned and lots of moisture got into engine compartment.
Battery went dead. Charged up battery but bilge pump did not work!
Found out the in-line fuse on the thin wire connecting to the battery was blown. Put in
new fuse and it blows right away. Should this thin wire be connected to +ve or -ve post of battery?
Assuming that this is needed only for the bilge pump, proceed to start the engine.
Engine starts up after typical priming and cranking. Runs good at high idle for a few minutes.
Lower idle speed and engine dies. Restart would work but dies after a few second. Reving has
no effect.

 

[Maclin]

Welcome! What model engine are you running?

 

[Fun Times]

Hi there, welcome to iboats!

You forgot to mention what Volvo engine model are you having trouble with?

Also we went ahead and moved your topic down to the proper sub-forum in hopes to get you the best information available for your engine model.

Thanks and good luck.

 

[dypcdiver]

Are you aware that the alternator takes over powering the fuel pumps etc. once the ignition is returned to the run position from cranking?
Might just be the problem.

 

[hoitoto]

Here are the model # etc.
4.3GI PEFS 4012015970
3869055
Drive unit SX-M 1.79
4112082709
3868893
transmission assembly
TSK SX-M
4111635216
3868844

Per the posting about the alternator takes over powering the fuel pump, in a typical car engine, the alternator charges the battery
and everything runs off the battery. I guess marine engine is different, wondering why. With the high humidity inside the
engine compartment, it is possible that the alternator has died due to moisture saturation. Is this hard to diagnose?
Also, can I somehow keep the fuel pump running, just to see if that is the problem, and to help diagnose the potential
bad alternator.

 

[Thalasso]

It could be a bad alternator. The fuel pump circuit picks up power to energize the fuel pump relay
If the system is using alternator output for continuing fuel pump operation, that may explain the alternator involvement.
There is a relay that goes from the alternator to the fuel pump.

 

[Maclin]

'Tis a safety feature...