MEP-005A with D298ER engine. Fuel issue????

Good Afternoon, Any help would be appreciated... I purchased this 1978 generator with 1300 hours on it about a week ago. The guy I bought it from said the last time its been run was about 3 years ago. So first thing I did was replace the fuel hoses that were leaking and all fuel filters. After priming the fuel lines with the battle short switch I tried cranking the unit. The unit will pick up and run for about 3 seconds and shut off. I have read the instructions on the door and it says to hold in the run position till 20 psi oil pressure is present then let off. Oil pressure gauge seams to works correctly. I have checked for voltage at the injection pump and 24 volts is present. I removed the fuel supply line going to the injection pump, plenty fuel is present. So then after reinstalling fuel line, I cracked each fuel line at each injector... very little fuel was being delivered to the injector. Used compressed air to try and see if the fuel lines were clogged and they were clear. So that leads be to believe the injection pump is faulty. Am I on the right path or is there anything else I should try before I remove the injection pump and and rebuild it/buy one???? oh, all fluid levels are good and the unit will run off of either when applied. Thanks for the help
Fuel pump is a Stanadyne DBMFC633-2604 MFG# 40-3050302