Occasional Diesel "hot engine" starting problem

[pcn1]

One for the diesel experts here ?

So its my 2004 Grand Cherokee with the 2.7crd Merc engine. It starts on the button when cold and it run's fine.
However I noticed about 6 months ago, occasionally if I stop for a few mins when the engine is hot, like at a gas station, then go to re-start if fails.
I turn the key, it makes a noise like its just "fired" but dies instantly and then the engine will just turn over with no life.
Ive learnt if I wait say 5 to 10 mins then try again it fires up straight away. A bit off a pain if your at the pump with cars behind you. Its done this say 12 times over the summer.

The jeeps done 107K, the injectors are all original, never been refurbed. Ive recently put in new glow plugs (but that wont effect hot stsrating?) and new low pressure fuel lines as air bubbles is a known problem but thats all good now. No sign of the dreaded "black death" either so injector seals are all good.

I dont seem to have any independent local Jeep mechanics near, and Im not sure if the main dealer is going to be interested in a 15 year jeep just to look and read any possible fault codes.
Besdies, God knows what they charge per hour !

Any idea's where I should be looking for the cause ? Or if by chance you know a good mechanic who can read jeep codes in Berkshire let me know (based in Maidenhead)

Thanks

[GreenV8S]

Do you have a lifter pump on that engine? If so and there's a heat related problem with it, I guess it could cause the sort of symptoms you describe. Ten minutes switched off could be enough to bring a relay with a heat-related problem back to life.

[pcn1]

These engines use mechanical low and High pressure fuel pumps located at the front of the engine.

[GreenV8S]

Could they be getting hot enough for fuel vaporisation to be a problem? It's much less common on diesels but still possible.

[LordLoveLength]

It's possible that one or more injectors is leaking when hot, the engine then can't build enough fuel pressure to meet the firing threshold during cranking.

You would want to see the fuel rail pressure when hot and cold cranking, which would be dealer level diagnostics or a diesel specialist

You could also do a leak-down test when hot - this should show up a faulty injector

[pcn1]

LordLoveLength said:

It's possible that one or more injectors is leaking when hot, the engine then can't build enough fuel pressure to meet the firing threshold during cranking.

You would want to see the fuel rail pressure when hot and cold cranking, which would be dealer level diagnostics or a diesel specialist

You could also do a leak-down test when hot - this should show up a faulty injector

Good call. I have read about leaking injectors causing "starting/running problems" but thought that would be from cold.
I'll try and find a local diesel guy and see what he can do.

Cheers