MF 203 not starting

   #1  

m7040

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Frederick maryland
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Kubota M7040, MF 203 industrial, ZD331, RTV 1100 , Kubota Minix excavator, Unimog 404
The old MF 203 industrial tractor was sitting for a few years. Wanted to bring it back to life and it would not start. Changed the fuel filters and the fuel lift pump and bled the system and checked for fuel flow at the inlet to the injection pump. Next loosened the inlet to the fuel injectors and cranked the engine until fuel was squirting out at the injectors. Started the engine and it ran for 30 seconds and then shut down as if running out of fuel. Repeated this a few times with same results. Suspect at this point that the fuel lift pump is not putting out enough pressure. Not sure what the pressure should be at the inlet to the fuel injection pump. The fuel pump was cheap but looked like the original and pumped ok. Maybe I will buy a replacement pump from the MF dealer as the next step and try again. Any suggestions?
 
  
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#2  
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m7040

m7040

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Frederick maryland
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Kubota M7040, MF 203 industrial, ZD331, RTV 1100 , Kubota Minix excavator, Unimog 404
Finally had a chance to look at the MF 203 again. The fuel lift pump seems ok and pumps up plenty of pressure and flow. It is the old style pump similar to those used in older car engines so pretty simple. The filters are full and no air coming out at the vent screw. There may still be air pockets in the diesel injection pump and it does not have a priming pump like some of the later injection pumps. So the only way is to crank it and open at the connection at the inlet to each fuel injector. Next I will hook up a remote starter switch so I can open the connection to each injector while cranking and close it when a good stream of fuel is squirting out. Safety shield and gloves required. More to come when I get a chance to look at it again. Several other projects are moving up in priority. Retirement just means that more projects are always underway but good to be busy.
 
   #3  

jetfiremuck

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Florida
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mf 2135 industrial
Finally had a chance to look at the MF 203 again. The fuel lift pump seems ok and pumps up plenty of pressure and flow. It is the old style pump similar to those used in older car engines so pretty simple. The filters are full and no air coming out at the vent screw. There may still be air pockets in the diesel injection pump and it does not have a priming pump like some of the later injection pumps. So the only way is to crank it and open at the connection at the inlet to each fuel injector. Next I will hook up a remote starter switch so I can open the connection to each injector while cranking and close it when a good stream of fuel is squirting out. Safety shield and gloves required. More to come when I get a chance to look at it again. Several other projects are moving up in priority. Retirement just means that more projects are always underway but good to be busy.

On the inlet to the injection pump from the lift pump there is a screen in there. remove and flush out with brake cleaner. those cav pumps are simple enough to work on.
 
  
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m7040

m7040

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Frederick maryland
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Kubota M7040, MF 203 industrial, ZD331, RTV 1100 , Kubota Minix excavator, Unimog 404
jet fire, great observation. Yes there is indeed a screen at the inlet to the injection pump according to my parts manual. Also there is a vent screw on the side of the injection pump that I saw on the parts diagram. So will clean the screen and use the lift pump to establish flow through the vent screw and then vent at the injectors. Hopefully that will make it start.
 
  
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m7040

m7040

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Frederick maryland
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Kubota M7040, MF 203 industrial, ZD331, RTV 1100 , Kubota Minix excavator, Unimog 404
Was able to get the engine started. For the benefit of others with similar Perkins engines when priming the system the procedure is to use the lift pump handle to pump up pressure on the fuel system. Then first open the vent on top of the filter until clean fuel comes out, next open two small vents on the side of the injection pump and pump until clean fuel comes out, then open the connections to the fuel injectors and crank the engine. Tighten the connections and now it is ready to start
 
 
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