Fuel Pressure

[Jrod 7]

For a while now my cars been a bit tricky to start when left for a few hours, it turns over for quite a while before it splutters into life.

 

I inititally blamed this on a faulty Temp sensor and didn't bother looking into it as I knew it was all being replaced along with ITB's. Well its all been done and its still the same, I don't think its anything to do with the map as it was exactly the same on standard management.

 

I've been trying to track it down and I think its to do with fuel pressure, or the lack of. If the car is left to stand there is no fuel pressure at all in the rail. If I prime the pump a few times before starting its starts normally as it should.

 

Is there a valve anywhere that should keep fuel pressure up when not running?

 

I found THIS thread but there doesnt seem to be a definitive answer?