Hard to start

[Jeffrey Hey]

After sitting for a couple of hours (cold motor) the patrol is very hard to start winds over okay but takes quite a while to start. Glow plugs seem to pre-heat for the same time as normal
Any ideas would be most welcome.
Nissan Patrol GU 3.0ltr DI 2002 model with 260K on the clock

[Tip12345]

glow plugs need testing