Fuel pump or bleeding problem

[Edward 14244]

I replaced oil and fuel filters last week (Universal 25XP) and today had the following problem: when I start the engine by turning the start-key in second position to activate glow plugs (which I need to do with a cold engine) the fuel pump first makes a rattling noise (or very fast ticking), then ticks normally. It never made that very fast ticking noise before. However, engine starts and runs fine. Coming back from my sail, with engine still somewhat warm I turn the key only to first position and push the starter button. Engine starts and dies after a few seconds. Happens a few times. When turning key in second position, again I hear the very fast ticking of the fuel pump for a few secs, then the 'normal' ticking, engine starts and runs fine.What is happening? I intend to bleed the fuel lines again tomorrow, but I don't understand that the engine can run perfectly ok if I start it one way but dies the other way. If air is still in the lines, the engine shouldn't work at all, should it? Can anyone help with this mystery? I am unfortunately only moderately technical......

 

[Stu Jackson]

Mystery

question - you said you replaced your fuel filter last week. From your description, you are getting air into the system after the engine has been running. The fuel pump rapid ticking means there's air in the system. When it goes away, it means it's pushed the air out of the system through the fuel return line and the engine works. So, it sounds like there's air getting in, and most likely at the fuel filter. Check the gasket at the fuel filter connection to the bracket and check the tightness of all the hose clamps on the fuel lines. Also check to assure that the vent on the top of the housing and the drain on the bowl are also tight. You're not the only one that this has happened to, see the link.

 

[Edward 14244]

Thanks, Stu

Your suggestions were very helpful. I went to the boat today and it appears there was air in the first Racor filter. Next filter was ok. Engine now seems to work well, so hopefully the problem is solved.The knurled knob on the injection pump bleed is broken -I didn't touch it, so must have happened a long time ago. This means that I won't be able to bleed that part if needed - can't get any movement in it. Does anyone know if such itens for the Universal can be ordered by mail-order in the US? I have some doubts that it would be available anywhere in Australia.