Hi All, My 2003 590SM seems to lose it's fuel prime after sitting for a couple days. When I go to start it after sitting a while it starts then chugs a few times then quits. The only way I can get it started is to pressurize the fuel tank and bleed out the air from the fuel lines at the injector pump, fuel filter and any fuel fitting I can open. After bleeding the air it starts then chugs a little then runs smooth all day - starting and stopping the engine no problem. Let it sit a couple days and the same problem. I checked all the fittings for tightness, checked the fuel filter gasket for nicks or cuts, no lines have cracks or are leaking. The fuel just seems to bleed back to the tank and lose it's prime. The fact that it initially starts kind of tells me that the problem is before the injector pump. Any suggestions?
Usually its the lift pump. The fuel bleeds back through it. Just change it and the gasket. There is also a check valve on the return line on the injection pump, but its usually not a issue.
Thanks Gary, I suspected the fuel pump because it doesn't pump up the fuel when you push on the plunger. I have to pressurize the tank to get the fuel up and air out. I thought there might be a check valve in the pick up line in the tank but I couldn't see any reference to that in any of the parts or repair manuals. Unless anyone has any other ideas I guess I'll order and change the fuel pump.
I suppose I'd try blowing air through the lift pump the way that it pumps and see if it clears any gunk out and starts pumping. Nothing to lose at this point, besides the time to disconnect the lines and reconnect them again to try it.