Engine loses power, dies after taking a break at the beach

[arcanex]

1993 Four Winns 4.3L V6 OMC out drive. Arizona boating (1300 ft MSL, usually 100+ F temperatures)

Hello All, long time reader, first time poster, looking for an assist. I've been experiencing this problem for nearly a full year with the symptoms getting progressively worse. I'm including all the information I have, so this may be long.

Around a year ago I started experiencing an issue like clockwork. The boat would start off the trailer fine, idle fine, pick up on plane fine, pull tubers and skiiers fine. We'd take a break, anchor for an hour or so, and start up again. The boat would start right up, idle fine, even pull out of the hole on plane fine, then 5 or so seconds after up on plane, lose power, RPMs, and die. It would typically start right up and we could pull a skiier out of the hole full power and not experience another loss.

This season, the problem is getting worse, especially the last couple times out. The boat will die a 2nd or 3rd time in the same way after the first loss of power. Now the engine is not starting back up very easily, or will start, struggle, and die multiple times without ever getting into gear. Last time, I went thru the cycle of starting it, getting into gear, getting about 100 ft, struggle and die maybe 5 times before it finally seemed to resolve enough that it stopped dying and I was able to get back to the dock with full power, a 5 mile run straight back without issue.

I've noticed a few things, the electric fuel pump, which was the only thing I've ever replaced 3 years ago is screaming as if it has a bad bearing. It's also too hot to touch within 5 minutes of the boat running. I pulled it off the engine, and ran it with no load and it's pulling about 8 amps at 12 volts, seems high although I can't find a spec on what it should pull. I haven't done a fuel pressure test yet. The heat and sound is the same if I pull fuel from a short hose out of a gas can. I replaced the fuel filter, same results. (Doesn't seem related to blockage from the gas tank to the pump) Engine running temps right in the middle of the gauge.

I cannot reproduce the dying problem in by driveway with muffs. Starts, idles, revs up what seems to be perfect. I'm about out of ideas beyond buying another pump and seeing if it fixes my problem. Help me iboats forums, you're my only hope.

 

[HT32BSX115]

Re: Engine loses power, dies after taking a break at the beach

I haven't done a fuel pressure test yet. The heat and sound is the same if I pull fuel from a short hose out of a gas can. I replaced the fuel filter, same results. (Doesn't seem related to blockage from the gas tank to the pump)

Howdy, Welcome aboard!


You might have a look at the fuel tank vent, pick-up screen (in the tank) and fuel lines. It does sound like an intermittent fuel starvation issue.

Start at the tank and work your way to the carb.

You could also get yourself a fuel gage (0-15 psi--- available at most auto parts shops) and observe the pressure at the carb when this happens.

I've noticed a few things, the electric fuel pump, which was the only thing I've ever replaced 3 years ago is screaming as if it has a bad bearing. It's also too hot to touch within 5 minutes of the boat running.

You didn't indicate what engine/drive model you have (you could have one of the (8) 1993 models or (4) 1992 models) Good thing is, they all likely used the same fuel pump.

If it gets "too hot to touch" you VERY likely have vapor coming out of the pump (vapor lock)

The fuel pressure gage might reveal evidence of that.

8A current draw for the pump is not out of line I would think but if it's getting hot, it doesn't matter. it's still heating the fuel.


I would probably put a TEE in the (output) fuel line and check the pressure. You could also even put a heavy clear vinyl hose on the output and look for bubbles to confirm but "too hot to touch" will absolutely cause vapor lock.


Cheers,


Rick

 

[DavidAM]

Re: Engine loses power, dies after taking a break at the beach

check tank vent, check anti siphon valve at top of tank, check screen at bottom of fuel pickup tube or in tube. Also try putting a clear sight fuel filter before the pump then you can always see if the fuel is coming to the pump. I had the same problems and i found a small screen inside my fuel tube. the pictures below show the original setup and the new setup I fabricated for $30.00 I also keep a few extra filters in the boat. Be sure to keep all the other filters and oil water separators in their current config.

Whats happening to your boat is your shaking up the tank then it settles a little during lunch and then stop up the lines.

here is the filter I used got mine from Autozone and don't worry if your boat is injection that only matters after the fuel pump not before its not under high PSI

 

[Maclin]

Re: Engine loses power, dies after taking a break at the beach

David,

What is an oil water separator? I know of a water separating fuel filter but not an oil water separator.

 

[HT32BSX115]

Re: Engine loses power, dies after taking a break at the beach

View attachment 160515

This is a temporary thing right?
A USCG check will reveal that the above type of filter is illegal in a sterndrive boat with an enclosed engine compartment.

 

[arcanex]

Re: Engine loses power, dies after taking a break at the beach

A sincere thank you for your responses. I'll take a look into the fuel vent, pickup, and lines. I rented a fuel pressure kit from Autozone but it turned out to be for road vehicles (obviously) and not the right connectors and the gauge was meant for much higher PSI readings. I will pick up the right connectors and gauge within the next few days. Regardless, I'll post my findings and where things go from here.

A few questions:

Why would the newest part on my engine, the fuel pump at 3 yrs old be so hot and loud? Is it possible a blockage has degraded it over time? How do the internals of these things function? Maybe the reason my last one gave out?

Again, thanks, and I'll report what I find.