Stalling Universal 5424 Engine

[ryderstk]

HELP.... I have a Universal 5424 Engine that is giving me fits. I bought the boat in April and have been working to get all the essential systems in working order and so far I have been stumped on getting the engine to run reliably... I started by draining the 20 gal original fuel tank. There was 15 gal of old fuel, of which 10 gal was water. I changed the oil in both the transmission and the engine. Both of which were free of any water. I replaced all the fuel lines, water lines, and all the filters, as well as a new elec fuel pump. I also installed a new heat exchanger and put in 50/50 water anti-freeze. I then hooked up an outboard tank in the galley, above engine to feed first into a Racor fuel water seperator, then to the elec fuel pump, then to the engine mounted filter.

Next I bled all the lines starting at racor moving to the engine mounted filter bleed screw and then to the injector pump bleed screw. Engine sprang to life after only a few attempts. I was at that time on a mooring at Davis Island in Tampa and needed to move to a marina closer to my house to finish the refit. It took me 3 hours to get to the other end of Tampa Bay, but she ran perfectly.

Whats the problem you might ask. Well, once I got the my new marina, I wanted to have the tank professionally cleaned and fuel polished. Which I did, and what a mess was in that tank. After 3 hours of cleaning and polishing, the inside of the tank was like new. I decided to let them remove the fuel that we used to clean the tank and start out fresh. I even replaced the racor and engine fuel filters to ensure that I was starting out with all new parts in the system once again.

I bleed the entire system by the book and once again, the engine purred like a cat. All was right with the world...... THEN the RPM began to fluctuate and finally the engine stalled. I bleed the system again, and could only run for a couple of minutes and then stall again.

Here is what is have check so far and still I have the same problem... Run a couple of minutes with fluctuation RPM then Stall...

1. Bleed Lines
2. Checked vent line clear, by trying to run with fuel cap off
3. Replace the return line and all hoses .... again

I am going to change the filters again tomorrow, but I am running out of ideas.... Soon I am going to have to call in a mechanic, but I wanted to try and solve the problem myself if at all possible.

Thanks,
S/V Island Fever

[DeniseO30]

don't know which one you may have, but some fuel pumps have a little strainer in the line that is not always noticed when they are installed. do you have full flow of fuel with the line disconnected from the engine? (into a bucket)

[bwindrope]

You have sure been thorough in trying to get her in good shape. I like the thought on checking the fuel pump, as the only reason I know of that a diesel will vary it's rpm is fuel related. That is, given that the engine has no mechanical problems which yours does not seem to have.

So with fuel, I would check:
A. Fuel pump work
B. Air in system (which you seem to have addressed with bleeding)
C. Injection pump trouble
D. Injector trouble

On this last note I would feel all of your injector lines to make sure they are pulsing, and since you are tackling everything anyway, I would pull the injectors and take them to your local diesel injection shop and have them cleaned and checked. If all of the above is OK and you are getting fuel to the cylinders at the right time and quantity, then I would have to start looking at serious mechanical issues. But that doesn't sound likely with you saying that it sometimes runs beautifully. Mechanical stuff doesn't come and go like that.

I would also run some high % biodiesel if you can get it to clean out your system. I did this on my Universal 5432 and after a tank or two and two Racor filters, I now have a spotless fuel system with out having to pay for polishing. If your diesel is fresh water cooled and runs at anything below 180 degrees or so, then I would change your thermostat to get it up closer to 190 to not build up soot in the system. Oh, the laundry list of things we do to keep these damn things working.

Good luck and best wishes.

[ATC]

Have you pulled the fuel pickup from the tank to confirm if there is blockage? If you need to call anyone for diesel work in St Pete, pm me for Terry Clarke's number.

[DeepFrz]

+1 on Absolute's suggestion above. As well as checking for blockage in the pickup tube check to make sure there are no air leaks in the pickup tube. Usually the pickup tube makes a 90 deg. bend at the top of the tank and there may be a shutoff valve there. It is an ideal place for crud to block the line.

[DeniseO30]

Ditto on the pick up strainer! they clog quick! even in new tanks such as mine. LOL

[DeepFrz]

Yes, as Denise says, there should be no strainer on the pickup tube.

[daddle]

Fuel vacuum gauge is invaluable in this situation.

[Maxs]

The Facet fuel pumps are the ones with strainers. Just in case, sometimes the valves takes air into the system.
Keep in mind that the 5424 should be bleeded fuel filter first, and injector pump last. Good luck!

[Boracay]

Its probably a silly question but when you replaced the filter did you fill the Racor with diesel, and check that the sealing ring and the "o" ring are both according to the manual?

The filter is below the tank as mentioned in the manual?

If you haven't touched anything else then you've air in the system and need to bleed, again according to the manual.

[ryderstk]

Good News.... Changed all the filters, re-bled the lines and engine is purring once again. Will take her out this weekend and give her a good shake down....

After changing filters 3 times hopefully I have all the bad stuff that was trapped somewhere after the polishing/cleaning.... Time will tell.....

Thanks for all the feedback...

[DeepFrz]

Were the filters dirty? If they were the polishing company didn't do a very good job. Most will run the fuel back through a 2 or 10 micron filter so it shouldn't ever plug your filters that soon.

[ryderstk]

I am thinking that one of the lines may have had some trapped fuel, or the fuel pickup tube had gunk in it. When they polished, they went through the sending unit hole... So the pick up line never got cleaned. The one thing I did, once I had the issue was to blow the pickup line clear with my compressor. Time will tell.............

[DeniseO30]

The summer after we installed the new tank in my boat, went on a trip to the Chessy, 4 filter changes during the trip.. at $30ish each for the R-24T I realized the error of my ways.. NEVER! EVER! TAKE "FREE" FUEL! (from a friend that changed his tank also) ALWAYS USE A FILTER FUNNEL! sorry.. I just had to yell LOL