Hopefully someone can help me with this one: my father-in-law has a 2005 Grand Cherokee 2.7 diesel. The problem is that when its started from cold, it immediately cuts out and won't start again for at least 90 seconds of churning over on the starter. Once its fires up again, it starts and runs fine for the rest of the day.
The fuel filter has been changed and our local garage has fitted a non-return valve in the fuel line as it was suspected the fuel may have been draining away but this has made no difference. We suspected the problem may be worse when the car was parked overnight with the front end facing slightly uphill, though we're not certain of this.
I'd be very grateful if anyone has any ideas?

 

no holes in the line or a small leak.
my 7.3 had barely a leak and thats what it used to do