One inop fuel pump on a dual pump set-up can cause problems. I don't recall if it is just starting problems or running problems or both off hand. Maybe after getting good connections at the pumps you can try running without the diode you added?

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.