[Vwdiesel] Occasional hard starting ...

[Derek]

I don't know if its just the fact that she finally rolled over 300K, but lately its been hard to start.  The symptoms are the same as if the glow plugs aren't working, but they are.  Sometimes you have to run the starter for 10-15 seconds, most other times, it'll fire instantly.  The only thing I can really think of is the check valves at the tank.  Any other ideas ??  Battery's practically new ... I am just at a loss of what it could be.

95 Getta, 1.9TD