D333 genset fuel lines

I was asked to help a friend get this genset going but I need a little help. the serial number is 66D3128  from what I can tell is either a D333C or a 3306 motor I think they were close to the same thing. we replaced the fuel pump primer and ran new fuel lines but can't seem to build -or hold fule presser. just wondering if we have it all plumbed right?  fule come in the clear line to the filter base then out to the hand pump then to the transfer pump. all the lines were missing when we started we do have fuel at the injectors when we cranked it over. I think we might be missing a T with a check valve for the hand pump? I think we are trying to pull all the fule through the hand pump into the transfer pump then to the injection pump.  it last ran about 25 years ago  

 [attachment=66726]20220208_202934.jpg[/attachment]

The D333C (66D) fuel system is not the same as the 3306.
The small passage priming pump on the D333C runs a parallel circuit.
The larger passage priming pump on the 3306 runs a series circuit.

Filter discharge goes to a tee on the transfer pump suction.
The other leg of the tee is supply to the priming pump then back to a port on the injection pump housing.
[attachment=66727]66D Transfer pump.jpg[/attachment]
[attachment=66728]66D FuelFilter.jpg[/attachment]

thanks for your help that makes a little more sense. I wouldn't get anything fixed without your generous help.