Volvo Penta 5.0 Gi Won't Restart when Hot

GCM2

Recruit
Joined
May 21, 2015
Messages
3
I have a 1998 5.0 GI Volvo Penta engine. The boat had sat idle for over 6 months with ethanol fuel in it. This made a number of problems. However after changing the low and high fuel pumps, emptying the fuel tank and replacing the gas with ethanol free gasoline, changing the fuel filter and pump relays and rebuilding the float mechanism in the fuel reservoir the engine runs fine. I have been testing to max throttle 4600-4800 rpm with no problems and great performance. However, if I run the engine hard and then shut it down, it won?t start again. When cranking I can hear several cylinder fire, but it never revs up. Occasionally it will backfire. It is fine again once it cools down. Any thoughts would be appreciated.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
I don't think ethanol fuel has anything to do with your issue and 6 months is not that long.

I would try running on an auxiliary tank and see if it has the same issue.
 

Gold Eagle Co

iboats Partner
Joined
Apr 20, 2015
Messages
85
Hey everyone,

Today's ethanol blended gas can actually start to go bad in as little as 30 days. That's not to say it's unusable at that time but you may experience some issues due to lost volatility of the gas. Over time that gas will gum up and can cause problems for your filters, carb, etc. Non-ethanol blended gas has a little longer shelf life but it will also turn over the course of a couple of months (will vary slightly based on quality).

The best practice when storing equipment is to fill the tank about 95% full, add a high quality fuel stabilizer, and then run it for a few minutes to ensure the entire fuel system is treated. We might be biased but we would recommend STA-BIL?...

Let us know if you have any questions.

Have a great day!
 

four winns 214

Senior Chief Petty Officer
Joined
Oct 25, 2008
Messages
757
A stab in the dark here, but I had a somewhat similar experience. Turned out to be a cracked rotor. It was tough to diagnose because the problem was intermittent. Replaced it and zero problems since.
 

GCM2

Recruit
Joined
May 21, 2015
Messages
3
I had hard failure of the low pressure fuel pump and replaced it. The engine seems to be running fine now and will restart when hot. I guess the pump was failing the engine heat at the end of a run would cause the intermittent failure. Thanks for all your replies. I now avoid ethanol fuel and do keep the tank full.
 
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