Trouble Shooting Tips
There are a few things you could check that may save you some time and money.
First you need to know what kind of pump you have, Rotary or inline, then it will help if you know what brand it is, Bosch, CAV/Lucas-Delphi, or Stanadyne these are the most common. For help in determining this you can click here for a few pictures.
Some pumps require high body pressure to run, some will not run with high body pressure.
1) Observe if you are getting any smoke when you crank the engine.
No smoke equals no fuel to the injectors,
If you have smoke but it won't start there may be other issues. (Bad injectors, low compression, or too slow of a cranking speed)
2) Check the supply of fuel going into the pump. Many people open the line, see fuel run out and assume they have enough, this may not be the case.
We have found that if you can get a clear line (available at many hardware stores, this does not have to be a high quality line, you are just using it to test, most any type of line should last for this) on the supply to the pump this will tell you what is happening. If you see more than 5 or 6 air bubbles per inch of line you have a supply problem,
3) If you are now satisfied that your supply is good and it still will not run there is one other test you can do in the field. Take an injector out and take the injector line loose from the pump, turn the line so the injector will hang on the outside of the engine in an area that you can watch it. Crank the engine over and notice if it bust the injector. You may need to leave the line loose at the injector until you get fuel. BE EXTREMELY CAREFUL NOT TO PLACE YOUR HAND UNDER THE INJECTOR TO SEE IF IT IS SPRAYING!!!! Diesel fuel at 2,000 plus PSI WILL PENETRATE THE SKIN!!!!!! Possibly killing you!!!! Another thing to note is you will not be able to tell if it is putting out enough fuel by looking at it. Most of the 40 to 100 HP tractors will put out between 50-90 cc's of fuel in 1,000 hits so at 90cc/1000 strokes that is 0.09cc's in one hit. That's not much!!!!
If you have good, proven supply to the pump, fuel up to the injector, and no fuel out of the injector. You have either a bad injector or a bad pump. You should take them both in to a fuel injection repair shop. If the injector is stopped up, chances are good you have damaged the pump also.