2001 2500 HD Duramax starting problem.

My friend has a 2001 2500HD duramax diesel and sometimes it wont start when he parks on a hill with the front of the truck on the uphill side. We have to prime it to get it to start and then its OK. It only happens when he is parked going uphill. He has taken it to the dealership and they are clueless.

Does anyone know what causes this and how to fix it?

Sounds like your friends truck may have a leak in the fuel system. On a stock Duramax fuel lines from the tank to the fuel pump, including the filter, are under vacuum. There are several QD’s (quick disconnects) that can produce vacuum leaks as well as the filter O-Rings. The Duramax common rail injection system is fairly complex and several things can cause hard/no starts including a plugged fuel filter, faulty injection pump and faulty injectors. Are there any other symptoms such as lack of power, white smoke, fuel in the oil (overfilled crankcase), or erratic oil pressure? A quick test for vacuum leaks is to connect a Kent Moore Vac/Pressure Gauge (http://community.webshots.com/album/73314886FLnSco) to the Schrader valve test port then pump the primer until hard. The pressure on the gauge will bleed slowly down through the return line. If it drops fast there is a leak. Also how long has it been since the fuel filter was changed? Is the bleeder screw O-ring in place and tight? For more info on the Duramax try.

The Diesel Page Forum (http://forum.thedieselpage.com/ubb/ultimatebb.php)

The Diesel Place Forum (http://dieselplace.com/forum/)

:)