Hummers: m1009 fuel system, throttle shaft, cross shaft

Question
!985 M1009 starts right off but dies quickly then needs to crank for an extended time to start again. Once restarted it runs great. Check valve or fuel pressure switch? Where are these items located in the system?

Answer
There is a check valve on the return line coming out of the top of the injector pump; remove it and blow through it to ensure it is unobstructed. The fuel is feed to the injector pump by a mechanical fuel pump so there is not a pressure switch in the system.

A common problem with the 6.2 is the throttleshaft seal for the injector pump will allow air into the injector pump and the vehicle will lose prime. This will cause the vehicle to be hard to start. Fuel may be visibly leaking at this seal or it might just be passing air into the fuel system. Inspect all other fuel lines and ensure they are not deteriorated or loose to eliminate any other simple causes.

If you determine the throttle shaft seal is at fault. Order cross shaft seal kit GM 14067404 and intake gaskets GM 14044976. Soak down the three torqx fasteners real good on top of the pump. Also soak down the allen head fastner behind the top of the inj pmp.


Ted