Hi, my charger cat 941 serial 70h1384 I can not start it anymore. I changed the diesel filter. Turning on the priming pump the air back, it is not clear from where.
To see this, I put a piece of transparent tube in the final section. Removing the filter I realize that it is not as full as I had left it but empties halfway.
By removing the filter and acting on the priming pump, nothing comes out from under the filter, only air is heard, is this normal?
How this engine works and weird ...
Help ,
thanks a lot to everyone .

what to check?
the engine is the same as the attachment

Hi uisum,
welcome to the BB.

If you have a stuck Injector Nozzle Valve you will have air from the engine cylinder blow back out from an Injector as a stuck open Injector Nozzle Valve can cause air to be pumped back into the Injection pump and cause the symptoms you have described.

I guess you have checked if someone has turned off the fuel taps under the fuel tank as you have fitted the clear line. Then remove one end of your clear line and check for good fuel flow from the tank.

Before trying to start the engine, when you bleed the fuel filter housing from the bleed valve on top of the filter and are pumping the Priming pump are you getting air free fuel flow from the filter housing bleed discharge pipe?

Next thing would be to open the governor lever fully, undo the fuel Injection pipes at the injectors and crank the engine to clear air from the fuel Injection pipes, are you getting fuel coming in small spurts from each pipe end?

Hope this helps.
Cheers,
Eddie B.

hello thanks.
I resolved, I unscrewed the injectors and turned the engine. He was full of air. At the end only diesel fuel came out. I heated the glow plugs well and started the engine. Finally it is on.
The engine that is in the image is 3304 or d330, I have not been able to understand yet.
Thank you for your precious help.
By Simo (Italy)

Hi uisum,
Thank You for letting us know you now have your engine running nicely now.
Well done my Friend.
Best Regards,
Eddie B.

Engine is a D330C (4-3/4" bore).
The 3304 did not come in until 70H2942

"Old wrote:

Engine is a D330C (4-3/4" bore).
The 3304 did not come in until 70H2942

Hello thank you.
In these links there is a 3304 which is the same as mine and the serial number is 70h1974
www.monniofficine.com/3512/
In the engine of my caterpillar there is a plate with year 1979.
So we are sure D330C? How many horses do you have?
In the link that I have attached them are professionals and have several engines.
I have some doubts

The engine in the picture is NOT a 3304 but the earlier 330C Series engine, they are not the same blocks or C/heads although they have the same bore size. tctractors

The engine in your picture is also a D330C. The 3304 uses a different water pump with large four bolt cover. Also has the large round cover on the timing gear cover case.
70H1384 is a 1970 build machine. Don't know why you'd have anything saying 1979. Are you reading the tag right? or may be a rebuilders tag?

"tctractors" wrote:

The engine in the picture is NOT a 3304 but the earlier 330C Series engine, they are not the same blocks or C/heads although they have the same bore size. tctractors

ok thanks you

"Old wrote:

The engine in your picture is also a D330C. The 3304 uses a different water pump with large four bolt cover. Also has the large round cover on the timing gear cover case.
70H1384 is a 1970 build machine. Don't know why you'd have anything saying 1979. Are you reading the tag right? or may be a rebuilders tag?

I see.
From the head gasket comes a silver plate with the inscription, year 1979.
Later I send you detailed photos.
The machine stickers have 941b.

I called the center officinemonni ( www.monniofficine.com/3512/ ), and they confirmed 100% that the engine is a 3304 cat. I have no words, I'm absolutely not expert.

:Aiuto: