Technical 2007 Fiat Ducato 2.3 multijet keeps cutting out at random

[geeki]

The vehicle is a motorhome so it's only done 27,000 miles, I have owned it for 4 years and have done about 6,500 miles in that time, whether that is relevant or not I don't know but it is stored outside through the winter months November to May.
It first cut out 3 years ago on our way home from the last trip of the season, restarted straight so I wasn't too concerned.
The following year almost 12 months later the same thing happened so I took it to my local service station they did a OBD scan which showed a fuel injector fault, due to the low mileage the mechanic advised me to just put some engine cleaner in and see how it went.
The next time it cut out I took it back and was advised to have the fuel injectors tested, the result of the test was that they were all faulty and should be replaced.
New injectors made no difference whatsoever so the garage replaced the fuel rail, fuel filter and checked the fuel pump pressure,, the next step was to have the ECU tested and rebuilt.
Nearly £2,500 later I am still in the same position, I have since replaced the fuel pump relay and main relay but that has made no difference either.

I have read numerous posts on various forums and cutting out seems to be a common fault with this engine but cannot find a definitive answer to what is causing it.
One thing I have noticed is that the last 3 or 4 times it has happened it was in the same place on the motorway whilst testing, about 10 miles from home.

Does anybody know if the fuel cap is vented or is there a pressure release valve in the tank as I have read on some posts, the reason I am asking is that I was wondering if a vacuum in the tank could be causing fuel starvation at around 10 miles.

Any advice would be much appreciated as I'm all out of ideas at the moment and it would be good to get it sorted before I put it away for winter. Brrrr

 

[LandyAndy]

What is the engine doing when it cuts out? High/mid revs, or when you are slowing up the slip road?

would be easy to just do a road test with fuel cap left off.

 

[geeki]

Hi LandyAndy
It used to seem that it happened mainly when slowing down but lately it has cut out going up hill, however I find that if I keep in a lower gear with high revs it doesn’t cut out.
I was thinking myself about running with the cap off to see what happens, I suppose it would rule it out anyway.
Thanks for your input I will give it a try.

 

[LandyAndy]

If higher revs stop it from dying then I doubt it would be vacuum in fuel tank.

If it is when release the acc pedal then it can be due to the flap in the throttle body shutting, and not enough supply through egr.

The throttle body is a known problem item on the early X250 Ducatos. Do you know if you have the standard item or the improved newer version?

 

[geeki]

I would expect it to be the original

If higher revs stop it from dying then I doubt it would be vacuum in fuel tank.

If it is when release the acc pedal then it can be due to the flap in the throttle body shutting, and not enough supply through egr.

The throttle body is a known problem item on the early X250 Ducatos. Do you know if you have the standard item or the improved newer version?

I don’t know but would expect it to be the original version, do you know how to distinguish between the two and is it a case of replacing the item or can it be checked and cleaned?

 

[LandyAndy]

The new part is
504351131
Google that and it will show you what it looks like which is very different to the old version, with the new version being in two sections that can be unbolted.

Be warned they are a pig to change as the bolts often, (always) snap when doing it.

 

[geeki]

The new part is
504351131
Google that and it will show you what it looks like which is very different to the old version, with the new version being in two sections that can be unbolted.

Be warned they are a pig to change as the bolts often, (always) snap when doing it.

Thanks I’ll check that out

 

[Anthony489]

Hi

Just to add to LandyAndys post, here are pictures of an original Wahler throttle body and a later replacement made by Magneti Marelli. The TB is part of the EGR process, but if its flap closes when it shouldn't the engine is starved of air. If this happens when driving along it will feel as though you have more engine braking than usual. Not sure if this fits with your symptoms, but if you still have the Wahler fitted you are in the minority as most will have failed by now.

 

[geeki]

Thanks for the pictures and the info Anthony,
I’m going to the van on Thursday to check out the TB

 

[LandyAndy]

I found with my TB that it would not always return to being open. It is powered shut but opens just with pressure from internal spring. So it was easy to move with fingers and returned easy and well. But when the system shut it whilst driving, as it will practically every time you come off the acc pedal, then it just didn’t always open, as it was being sucked shut. I assume to weak spring??? The TB is only powered shut, and has no idea where it is, or what it is doing.

Just a thought