Troubleshooting an injection pump no start complaint
In order to properly troubleshoot a Stanadyne DB2 application, you must insure the following conditions are met:
1) Voltage – You must have the correct voltage to the shut off solenoid and to the cold start advance solenoid.
2) You should also have the pump properly timed. Please refer to the manufacturers timing information for complete timing instructions in the tech manuals.
3) You should also have a solid stream of return before the pump can achieve starting capacity. Return can be measured here. You can also attach a clear line to check the return for air bubbles here.
4) You should also have a minimum of 150-200 cranking RPMs. If your batteries are weak and you are not attaining the minimum cranking, your vehicle will not start.
INJECTION PUMP BLEEDING
Once you have satisfied these four requirements, the injection pump should be bleed. This is best done by attaching and properly tightening the lines at the head of the injection pump, and loosely attaching them at the injectors. As you are turning the vehicle over, you will begin to get a fuel foam, a mixture of air and fuel, coming out at the line connection, at that time go ahead and lock down the line nut to the injector. Repeat procedure until all lines are bleed completely.
If after doing this procedure the vehicle does not start, please do the following:
1) Attach a clear line to the return side of the injection pump and inspect for air bubbles. If you have air getting into the system, correct the problem before proceeding.
2) Attach a hose directly from the injection pump to an alternate source of fuel. You will need approximately 2-5 gallons for this test. You will need to bypass the entire fuel system, including the lift pump, for this test to be done properly. The injection pump has an internal supply pump that will pull fuel from the source.
If there is still a problem consult a diesel shop about rebuilding the injection pump.
Copied from the 3rd page of the CUCV FAQ sticky