My Father has a Doblo 1.9 JTD which will not start unless it is left to cool down for around 4 hours. It has been in the garage several times, - new glo plugs & fuel pump. He has wasted lots of money on this.

(The petrol station are not happy when he leaves it running to fill up !!)

Any Ideas?

Firstly welcome to the forum and I hope we can be of some assistance

Secondly I haven't a clue why it wouldn't start from warm, as when the engine is warm it's easier to start

Now if the glow plugs and what I was going to suggest fuel pump have been checked or changed then there aren't really many other things in the starting procedure left to check... I'll rack my brains a bit and see if I can think of anything.

Is it fine when the engine is running warm, no strage noises etc? Have you checked fuel filter? What is the problem whilst starting, does it turn over but not kick in, or does it struggle to turn over? Another possibility is a problem with the ECU?

Ok an update on more things to check:

Check that the air filter is fairly clean and isn't blocked this will bring arise to more problems when it's warm than when it's cold!

Check that any sensors haven't come loose or aren't working properly, as this is another most common problem to arise more when warm, especially lambda sensor (please excuse my ignorance if diesels don't have them I can't remember)!

Check EGR valve, see this post for their problems!

tell the garage to check the solenoid vacume control valve for the anti run on butterfly in the inlet tract as if this valve fails ie leaks it suplies vacum and shuts the run on butterfly depriving the engine of air giving the impresion of fuel starvation

this does not have a fault code in the ecu but by starving the engine oif air
can bring up other faults such as air flow meter egr or boost presure

I got the same problem on my doblo deisel van. it doesnt start when engine is hot, engine turns over but doesnt kick in. i poured water over the fuel pump in a desperate atempt to get me going, then it seemed to work. which may sudgest a solinoid, or fuel pump? my mechanic is looking in to it for me. Does anyone know anything of this problem? thanks.