Stalling Universal M3-20B

[sailingdoc]

Recently bought Ericson 30+ with a repowered Universal M3-20B diesel. Engine ran fine initially but about a month into the season, it started stalling frequently. Was able to start most of the time but it created some scary situations in crowded seaways.

I tried replacing primary and secondary fuel filters. The primary was filled with gunk and some water in the separator.

After this didn't fix it, I resorted to local Universal certified mechanics. He replaced all of the rubber fuel lines from the primary through fuel injector pump. Also replaced the spring and stop/pivot that connects the stop cable to the stop lever and throttle arm. This seemed to fix things but four sails later, it was stalling again.

Fuel pressure measurements suggested the lift pump wasn't keeping up with demand for fuel and pressure was going negative. So... there is now a new lift pump. Pump had some corrosion inside which tech thinks was from water. Still stalling. Fuel injectors have been tested and have an appropriate spray pattern.

The engine stalls whether drawing from my tank or from a clean tank plumbed in after the primary at the marina.

Any thoughts? The only fuel system left to address is the fuel injector pump and the mechanical governor. I understand that the later fails almost never.

Getting to be very frustrating - and expensive.

Anyone have this experience with their engine? Solutions?

Thanks!


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[Lepke]

You have an organism problem. Bio organisms that created the gunk in the filter is throughout the fuel system.Water should be drained from the primary filter bowl any time it's observed. Organisms can grow anywhere there is water, but usually in the bottom of tanks and rarely used lines. Contaminated fuel doesn't burn as hot, sometimes causing stalls or the engine fails to reach full rpm. Organisms can also form on fuel pump valves allowing some of the pressure to go backwards or block the flow.
When I tackle a dirty fuel system, I'd use Archoil AR6200 at 3x the normal rate. You want to kill everything in the fuel and tanks dead. The conditioner also helps the diesel separate out the water so the primary can catch it. It disolves sluge and dirt so the filter removes it from the system. And it makes a more complete burn. Archoil is available at ebay, Amazon and better marine stores. Archoil | The Latest Developments In Nano lubrication A byproduct will be better mileage.
Water in the fuel can damage fuel components because it expands as it turns to steam. Water turning to steam expands 16 times, more expansion the higher the temperature. It also causes corrosion and rust on steel items. Zinc coatings aren't used on steel in contact with diesel because the fuel reacts to zinc.
If you don't have a vacuum gauge between the primary filter and the lift pump, I'd put one in. It lets you know when the primary filter is becoming plugged. I would put in a 2 micron filter in your primary until you get the fuel clean so the debris stops at the primary. It also helps to sail in some rougher water so you get a good scrubbing in the tanks.

[DeepFrz]

It also helps to sail in some rougher water so you get a good scrubbing in the tanks.

Please don't do this until you have manually and thoroughly cleaned your tanks.

[daviddiscenza]

I seem to have the same problem as sailingdoc with my Newport 33. DeepFrz, just how does one go about thoroughly cleaning the fuel tank? Can you point to any articles. Any recommendations are much appreciated.

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[Island Time O25]

Originally Posted by daviddiscenza

I seem to have the same problem as sailingdoc with my Newport 33. DeepFrz, just how does one go about thoroughly cleaning the fuel tank? Can you point to any articles. Any recommendations are much appreciated.

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A friend just went through such cleaning when he was helping a buddy who boat a 30+ year old boat. The tank did not have any cleaning hatches so they just cut one out and epoxied a screw on cover with the metal epoxy from HD. He said there was about 1-2 inches worth of sludge in the bottom. They loosened it with some kerosene and pumped it out with electric pump. Then repeated the process several times until all the sludge was gone. He said normally if he'd be hired to do this job (he's a marine professional) he'd recommend just changing the tank as it would be cheaper than paying him for all that work. But this was his good buddy who was on a limited budget and had to leave next day for a trip down South so he figured this would be the quickest and most economical way to do it.

He said there would be no way to get rid of all that sludge without an access hatch big enough to do that cleaning.

[bmm32005]

I had the same issue with a Ericson 32-200 I used to own. Mine would run fine with a full tank of fuel and stall below 3/4 of a tank. I found a pin hole in the soldered fitting on the pick up tube on the fuel tank. Pull it out and look close.

[bmm32005]

I had the same issue with a Ericson 32-200 I used to own. Mine would run fine with a full tank of fuel and stall below 3/4 of a tank. I found a pin hole in the soldered fitting on the pick up tube on the fuel tank. Pull it out and look close.

[daviddiscenza]

bmm32005 That's interesting. The engine stalled when the fuel gauge read 3/4 full. Thanks for the tip.

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[daviddiscenza]

My boat is a 1986 Newport 33. If I wanted to change the fuel pickup tube, where would I go to find a replacement? These probably aren't a "one size fits all" item.

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