Bukh DV20 madness

[unclebraddah]

I posted this on the classic boat thread but I am desperate. Motorheads are people too!

Hello. I have a Bukh DV20 built in 1973. I am sorry I dont have engine # but I hope they are fairly standard. My engine starts, and just before reaching normal RPM's dies. It will keep puttering if I keep the starter going.
It happenened all of a sudden. I needed to put a new valve cover gasket on because it was leaking oil. A minor maintenance issue. Of course I thought air in the fuel so I put a clear return line off the filter bowl back to the tank. yes there is air.
I have cleaned the lift pump and removed that little filter, It seems to be pumping fine.
I have replaced the Filter Bowl filter and seal and even tried running it without it. No change.
I have resealed Banjo fittings.
I have completly taken apart and put back together the Injector pump.
I replaced the high pressure lines from Injector pump to injector.
I have cleaned and inspected and retorqued injectors.
I loosened the rear High Pressure(HP) line and it kept running(with starter help)
I loosened the front HP line and it stopped.
I switched injectors and it remains that if the front HP line is loosened the engine stops dead.
I hooked up an electric fuel pump directly to the filter bowl from a supply above the bowl.
I Checked the Manual Govenor Spring wire to make sure it was caught in it's proper holes. It is but there is no response or acceleration if the shaft is turned, yet there is a return.

So...today I will check the Valve vacum system above the vales and am getting ready to tackle inspecting the centrifugal govenor.
But I feel it is something simpler having to do with me changing the valve cover gasket. Did I not adjust the compression lever proper? If so did I do valve damage? Everything looks OK. I have compression.

I really like this engine but it has been down since April. Im getting so frustrated I am looking at other engines infourtuantly. All the forums say to call you guys. It is a 12 hour time difference as I am in Hawai'i. So it is difficult and I want to make sure I have the right answers to any questions you might have.
You're thoughts are appreciated.

/forums/images/graemlins/laugh.gif

 

[Talbot]

I went through a torid 3-4 months with a similar problem eventually totally replaced all the pipe from the tank to the engine, and a new much more expensive filter system. Discovered that the problem was the attachment on the tank converting the vertical tube inside the tank, to the fuel pipe. Some plonk had used ptfe tape to ensure a sealed fit - yep guilty!

I remade all the connections using a special "lock n'seal" which sealed the connections and worked as thread lock on the connections as well. Worked perfectly ever after!

 

[unclebraddah]

Thanks for that! I actually had a strange issue yesterday. I changed the way my water seperator off the tank was set and now it wont even start just to die. So I got that on my list as well. Clean inspect(although its a new racor filter.)

 

[Talbot]

sounds like a possible starting point

Good luck

 

[Bilgediver]

I loosened the front HP line and it stopped.
I switched injectors and it remains that if the front HP line is loosened the engine stops dead

***************************************************
I would suggest you remove both HP pipes from the tops of the HP fuel pump and see what happens when the engine is turned over.

I suspect one pump with approximate a dirty movie while the other will just dribble..

This suggests that the injector pump spring has broken!!!

You will need to remove the pump and take it to a service centre.
You have answered your own question....!!!!!!

 

[unclebraddah]

I have taken the injection pump apart. Springs in tact and no considerable wear on pistion or sliding cylnder sleeve. Both delivery valves spurt fairly even. About six inches high in big drops. Should it be a high pressure stream like on top of the filter bowl in the return?

 

[Bilgediver]

I have taken the injection pump apart. Springs in fact and no considerable wear on pistion or sliding cylnder sleeve. Both delivery valves spurt fairly even. About six inches high in big drops. Should it be a high pressure stream like on top of the filter bowl in the return?

**************************************************

No this is what I was referring to....Satisfactory spurts...You will not get pressure with the injector disconnected..

If you can hear both injectors squeeking when connected then all is fine however if only one squeeks then the injector needle has hung up and needs servicing . If both squeek the fuel system is OK then the fuel system is probably ok so maybe a compression problem.

In spite of the quest for compression testers you can quite often check compression in a rudimentary way by removing the injector nuts and seeing if you can hold the injectors on the seat while cranking..If you can then things aren t too good in that department and either the decompressor is out of adjustment or leaking valves or rings.

A good test for leaking rings is to try and squirt som lub oil into the air inlet and first crank over decompressed then test the compression with the starting handle.

 

[cliff]

Try opening the throttle a little before starting the engine. If this cures the problem the tickover speed is too low. The Bukh engine starts on full throttle and once spinning the governor cuts back on the fuel. If the tick over is too low the engine will stop.
---------------------

Artificial Intelligence is no match for Natural Stupidity