I bleed the injectors and get air. The tractor will then start but only run for 10 to 15 minutes. I bleed the injectors again and get air. Seems to be sucking air from somewhere but I cannot figure out where. Any ideas?
1993 NH 2120 (the best), 1974 MF 135 (sold, but solid), 1947 Farmall A (bought, sold, bought back, sold again), 1956 MH50 lbt (sold, in 1980, darn it)
Cracked hose or hard line between tank and pump, or loose fitting, though I'm sure you've checked those. Fuel cap not vented might add to the trouble. Does your if have a lift pump or gravity to inj pump?
Jom