I have seen similar posts but have yet to see a definitive answer so I thought I would start from scratch to see if anyone can help.
I have a Hymer motorhome based on a 2002 Fiat Ducato 2.0 JTD. For a while now it has been cutting out when under strain (climbing hills or overtaking).

It only does it when fully up to temperature and only in warm weather.
It will cut out with no warning lights just the ignition light coming on and can generally be started again within a minute or two.
There are no error codeds stored on the ECU and no warning lights after it restarts.
I have, so far, replaced : The Crank timing sensor, Air Flow Sensor, Fuel and Air Filters, with no joy. Any advice please?

What did you read the codes with generic readers generally won't read generic or manufacturer specific codes.

A basic reader from Machine Mart

Do you know what fuel system it has on it.
Is it the early diesel or common rail (high pressure)

moodrater said:

What did you read the codes with generic readers generally won't read generic or manufacturer specific codes.

Click to expand...

Meant to say "won't read generic or manufacturer specific codes"

Does it always take a similar time before it will restart, a can of freezer spray / compressed air to cool the crank sensor, pump regulator, rail pressure sensor may be all you need to find the problem if so.

Good idea. Having already replaced he Crank sensor I am beginning to suspect the Fuel Pressure sensor but as they tend to be quite expensive I am looking for other ideas before throwing more money at it. The biggest problem is that in the current cold weather it will not play up, so using the revers or your suggestion, I could use a heat gun (with care) on the various components to see if I can force the fault?

Common rail.

Made the same mistake again above, tired, pending codes I meant. I suppose heat gun with care might work for the rail sensor, crank sensor, you'd probably never get enough heat into the pressure regulator without damaging something.

just an idea...I had a motor,different type and petrol,that did the same,found out it was the fuel vaperising due to heat,sorry can't remember how I fixed it,too long ago...good luck

Ok, purchased a USB diagnostics cable : Error Code P0191 Diesel Pressure Control. Have replaced the High Pressure sensor but still no Joy : Readings :
ERROR DETAILS:
Fault status: Signal not valid
Odomiter: 67848 km
Engine speed: 2606 rpm
Engine Temp: 81.2 C
Fuel quantity: 44.22 mg/i
Fuel pressure: 928.3 bar

Any Ideas?

1 Month later, after replacing pressure sensor, same error P0191 :

ERROR DETAILS:
Fault status: Signal not valid
Odometer: 67848 km
Engine speed: 2350 rpm
Engine temperature: 80.5 °C
Fuel quantity: 44.45 mgli
Fuel pressure: 907.8 bar

Only cuts out when fully up to temperature (around 80c) and only under some strain between 2K and 3K rpm. I am baffled

Maff172 said:

Only cuts out when fully up to temperature (around 80c) and only under some strain between 2K and 3K rpm. I am baffled

Click to expand...

maybe some use..

https://www.fiatforum.com/ducato/330405-2003-ducato-11-2-0jtd-cutting-out-issues.html

P0191 fuel pressure high/low? Next step would be looking towards the pump or injectors. Rarely is the sensor at fault after all it is only there to pass info back to the ECU.

Worth a try (it's cheap) is running a bottle or two of injector/fuel system cleaner and giving it a few good runs.

When it cuts out and it the starts again (after cooling a little) does it cut out again soon afterwards/few more miles down the road.

Yes. Once up to full temperature it will continue to cut out every time it comes under strain. I can get it home by keeping it in a lower gear on any hill.

Just done an injector leak off test and it does not look as if any of the injectors are faulty. Which sort of leaves either the Low or High pressure pumps. Any thoughts?

Not sure if this applies to you but I have extended the wiring to the injectors on this model due to tightness, dont think there was any relevant errors and most were passing by tourists but it done the trick on many occasions as always received a thank you call/card or box of chocs

Anyway worth a quick look.

The injector wiring seems to have pleanty of free play so I don't think it's the problem. Just seems to lose presure under certain conditions but only when fully up to temperature and only under load for a period of time (i.e. long gradual upward hills). Seems to pull OK up steep hils in a low gear. Always cuts out and will restart after a few minutes but leaves code P0191 in the ECU.

Still having problems so I thought I would put the full story up here to see if anyone has any ideas (Please).

The van is based on a 2002 Fiat Ducato (244) 2.0 JTD which has done around 48K miles. It cuts out only when fully up to opperating temperature on a warm to hot day (when the fuel has warmed up). It cuts out when the engine in labouring (i.e. on any type of gradient in a High Gear at aroung 3K RPM or lower). I can get up the hills by using a low gear and keeping the revs above 4K.
The engine will re-start after no more than a minute. There is no warning light but reading the codes goves P0191 suggesting a fuel pressure problem. Have replaced Presure Sensor, Fuel Filter, Air flow sensor, Crank sensor. Recently had diesel specialist check HP Pump and injectors and they say there is no problem there, they also replaced the small green O ring on Pressure Regulator as it looked a bit warn but still cuting out.
Anyone have any ideas (no matter how obscure) ?

going of what you have said I would suspect the fuel tank breather is blocked

Is there a breather other than the one in the filler cap? I have checked the filler cap and it is allowing air in. And when the van has cut out it tends to have positive pressure behind it rather than negative pressure.