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

 

[geeki]

Only just got around to working on van again got it uncovered this week and started looking at Throttle body.
Still not sure which model TB is fitted but have found that the butterfly is open all of the time both when ignition is off and when the engine is running.
Any ideas

 

[LandyAndy]

The throttle body being stuck open won’t cause any problem apart from a slightly lumpy shut down of engine. More of a problem is if it is shutting when not wanted.

 

[geeki]

Thanks Landy Andy,
I was wondering if it might be sticking both ways. Going to do some more testing with my mate to operate the accelerator and see how it performs then. otherwise it’s back to the drawing board any more suggestions would be appreciated.

 

[LandyAndy]

Thanks Landy Andy,
I was wondering if it might be sticking both ways. Going to do some more testing with my mate to operate the accelerator and see how it performs then. otherwise it’s back to the drawing board any more suggestions would be appreciated.

The only times the TB moves is when it wants to use the EGR gases, or when shutting the engine off. A diesel doesn’t use it like a petrol engine where it moves with acc pedal. Easiest way to check if moving is to turn engine off with pipe disconnected to the TB. It should close and after 1 minuet open again.

 

[geeki]

Tested throttle body and it seems to be working (opening and closing as engine runs)
Put it all back, fitted new battery as it wasn’t holding charge.
Road tested it last week approx 20 miles up the motorway and back with no issues.
More testing this week

 

[geeki]

Another update
Been out today for another test run, engine cut out on motorway after about 12 miles then ran ok for another 15 miles back to base.
Noticed that there was a significant fuel leak from 2 injector leak off pipes, don’t think that can be the cause but ordered some new pipes and connectors.
Bought myself an OBD2 scanner which showed codes P0271 and P0268 cylinders 3&4 injector circuits high, and code
P0697 sensor ref voltage C circuit open.
I’m thinking wiring loom or injector connectors.
Has anybody got any ideas

 

[geeki]

I had new injector connectors fitted but made no difference.
I have read on various websites that I should be able to measure a 12v current at each injector.
I have tried using a multimeter with the positive probe to the + side and negative to earth but cannot get a reading, could this be the problem

 

[Communicator]

I am seriously doubt that you will be able to observe the injector voltage with a modern multimeter. An oscilloscope would be necessary.

I do not know what the duration of each injector pulse is for a Multijet, but the name itself is derived from the fact that there are multiple injections in each cycle. This suggests shorter pulses than thosed used in a JTD (unijet) engine.

Fiat eLearn for the x244 2.0jtd provides some info. This has the injector pulse in two parts an operating pulse of at 80V for 0.3mS, and a maintaining phase at 50V for perhaps 0.4mS. Presumably the amount of fuel injected is controlled via the common rail pressure, and not by extending the injector opening time.

Having followed @grachal 's thread "Ducato 230 2.0 JTD Engine dies all the time", I am inclined to wonder whether the cause of your problem could be similar. The thread is well worth browsing. Here is a link, see post #42.

 

[geeki]

Thanks Communicator, That is food for thought and I'll certainly check that out it does seem feasible, I guess there is some sort of Pre-filter around the pump which could momentarily restrict fuel flow.
I just wonder if that was the case if it would throw up the same high injector circuit codes.