T4 cuts out on hot days

[Darryl]

My t4 2.5 petrol has been a great servant to me for 2 years now....but, if the temperature on the day gets to 35 or more it will just cut out. I leave it for 5 minutes and it starts up and drives away. The engine temp only gets just above 1/2 way and it doesn't lose coolant or have symptoms of overheating. The fans are working fine and I have also tried having the bonnet propped up a little while driving. It seems the problem is caused by weather temp rather than engine temp. After 2 summers of this problem I'm not prepared to endure this for a 3rd as it did it again last week when we had a 35 degree day having not done it since last summer. I am going to have to replace the vehicle sadly because no one can establish why this problem exists. Please help!

[AALocksmiths]

When it doesn't start what 8th the immobiliser light doing in the cluste?

What's fuel pressure like?

When it stops and you try to start it again what happens, starter motor engages but the engine won't fire up or completely dead?

[Darryl]

When it doesn't start what 8th the immobiliser light doing in the cluste?

What's fuel pressure like?

When it stops and you try to start it again what happens, starter motor engages but the engine won't fire up or completely dead?

Has ignition....cranks and just won't go until cooled down. Strange thing is its not that hot. Well, the engine doesnt seem that hot, just needs the bonnet up for a few minutes to let the heat dissipate. fuel pump, relay etc. new and still has always done it. Fuel lines insulated, insulated the exhaust as well to try keep it cooler under the bonnet. I have the belief that the fuel is vaporizing or somehow getting an air lock at high under bonnet temp. But about to give up on it. Problem being that the thing is such a good van and I don't really want to sack it!