HELP--- generator wont stay running

[Peggy & Ed McStay]

gen will start and run for about 2seconds then stop. what is happening
is the start -stop selonid closes off the fuel to the injector pump.
now i can make the thing run if i reach over and hold the cutoff lever
on the injector pump open. it will run all day. have looked at the oil
pressure safety switch. have disconnected it and tried to run gen with
the same results. what am i not looking at. need some ideas


ed and peggy mcstay
"lonesome dove"
35ft fc rb
perkins engine with kohler gen.