Volvo 8.1 Gi Abruptly Shuts Down

[TomP]

2007 Volvo 8.1 Gi (sn 4012210765)

Here are the facts of our problem:
- Engine has performed fine for 7 running hours this season prior to yesterday. Gas in tank is from last season but I always use Lucas Oil ethanol and stabilization treatment.
- Drove 10 minutes yesterday and anchored for 2.5 hours. Halfway home the engine abruptly quit with no warning. Engine restarted and ran fine 3-4 minutes and quit again. All gauges including the temp gauge looked normal.
- Today before going out I reset the kill switch to try to rule that out as the issue. I then started the engine and let it idle 5+ minutes until reaching full operation temperature. Then ran the boat at various speeds for 12-15 minutes including normal performance at wide open throttle. All gauges looked normal. Around the 12-15 minute mark the engine abruptly quit again just like yesterday with no warning. Restarted and ran fine thereafter but would abruptly quit three more times after 3-4 minutes including once at idle when I was pulling up to the dock.
- At the dock I couldn't seen anything wrong in the engine compartment, and all fluids looked good. The starboard exhaust riser was a little warmer than the port side, however.

Any help would be much appreciated. Thanks in advance!

 

[alldodge]

If your not getting a beep when it shuts off I'm thinking a bad connection or relay is opening.

 

[TomP]

Thanks alldodge.

Update: I went out again and idled for 23 minutes before the engine quit like before - just like turning off the key. After a few minutes I restarted and idled for 40 minutes and then ran at cruising speed for an additional 20 minutes with no problems. For good measure I cleaned the battery terminals and cables and manually tried to make sure the engine wires, fuses and relays weren't loose. As of now the problem is not recurring, but I am not sure why it started initially and why it stopped. Any additional thoughts or suggestions?

 

[alldodge]

The relays are cheap, I would go to local auto parts store and replace them. Find the fuel pump and ignition and just replace them. It should be the larger ones but not positive

3841366 smaller (2 each)
3858809 larger (3 each)

 

[TomP]

Good idea. Thanks again.