Technical Ducato 230 randomly stops after 5 min of driving

[Daka]

Hello! Since a few months I am trying to solve a problem with our Fiat Ducato 230 2.5 TDI (1996): The motor randomly stops, usually within the first 5 minutes of driving. It can't be restarted immediately, but after approximately 2-5 minutes the engine starts without any issues and usually works without any problems for the rest of the trip. All electronic devices seem to work properly, also during the phase the engine doesn't start.

I have already checked/replaced the following:
- exchanged the starter battery
- pressed the crash switch
- cleaned and measured resiatance of mass cable / ground cable of starter battery
- exchanged the diesel filter
- checked cleanliness of filter within the diesel tank

I am thinking it might be a flaw in the injection pump, the immobilizer or some air entering the diesel tubes.

Do you have an idea how I can narrow down the root cause?

Thanks so much for your hints and ideas.

 

[Communicator]

Hi,
Welcome to the forum.

I could be wrong, but air leaking into the fuel line seems to be the most probable cause. Once the air bubble reaches the injection pump, fuel will not be injected. With air swept through engine then runs OK, but why the need to wait for several minutes?
I have seen a suggestion in an earlier thread, to connect a temporary fuel supply, and test with that.

I have thought about the immobiliser interupting the supply to the pump stop solenoid, but you would have to remove the immobiliser, before making any tests.

 

[Daka]

Thanks a lot for your message and your thoughts! That's awesome.

Did I get you right, that the fact that the engine remains unstartable for several minutes is strange: In case it was caused by an air leak, it would probably not result in several minutes of waiting time before the engine can be started again? And therefore it might rather indicate a problem with the pump stop solenoid?

Is that correct?

 

[Communicator]

Thanks a lot for your message and your thoughts! That's awesome.

Did I get you right, that the fact that the engine remains unstartable for several minutes is strange: In case it was caused by an air leak, it would probably not result in several minutes of waiting time before the engine can be started again? And therefore it might rather indicate a problem with the pump stop solenoid?

Is that correct?

As I said, I also considered a possible problem with the immobiliser / stop solenoid. The few minutes waiting time could be due to waiting for something to cool down, but then why does the fault then not re-occur? If you are prepared to remove the immobiliser, then it is reported as being relatively easy to connect the stop solenoid directly to the ignition key switched supply (IGN+), which normally supplies the solenoid via the immobiliser.

 

[Daka]

Thanks! Yes, I am ready to remove the immobiliser permanently. During my research until now I had only found manuals which seem to work for different models only. Do you have an idea where to find a detailed description on how to deactivate the immobiliser for our Ducato 230 2.5 TDI (1996)?

 

[Communicator]

Thanks! Yes, I am ready to remove the immobiliser permanently. During my research until now I had only found manuals which seem to work for different models only. Do you have an idea where to find a detailed description on how to deactivate the immobiliser for our Ducato 230 2.5 TDI (1996)?

There are several older threads relating to immobiliser removal. They may be found via a forum search. If your immobiliser is secured to the injection pump as in later x230 models, then you will need to grind the heads off the fixing bolt. I recommend full research before commencing, as there are some reccommendations as to location of the cut. If I remember correctly, the bolt heads are partly countersunk.

 

[RalphM]

Try running it with the fuel cap loose it could be a blocked breather.

 

[Daka]

Try running it with the fuel cap loose it could be a blocked breather.

Hi Ralph, thank you for the hint. We went with the car on a weekendtrip. After driving approximately 2km I turned the fuel cap loose. To my surprise at this moment a loud sound of air blowing in or out occured. There must have been high or low pressure building up inside. Does that indicate a blocked breather? If yes, is there a way I can fix it? The problem of the engine stoping did not occur on the 200km trip.

 

[RalphM]

It sounds like you may have a blocked breather the sound is air rushing into the tank the breather could be built into the fuel cap have a good look at it when they are blocked the vacuum builds up as fuel is used and stops fuel being fed to the engine

 

[Daka]

There are several older threads relating to immobiliser removal. They may be found via a forum search. If your immobiliser is secured to the injection pump as in later x230 models, then you will need to grind the heads off the fixing bolt. I recommend full research before commencing, as there are some reccommendations as to location of the cut. If I remember correctly, the bolt heads are partly countersunk.

Hi Communicator, thanks. I took some pictures of the fuel pump this weekend, as all the descriptions on how to remove the immobiliser did not really fit our set-up. I assume that our immobiliser is not placed at the pump but right in the middle between the gas filter and the pump (s. pictures). Am I right? If yes, any idea what its name is in order to look for a manual how to remove it? Thanks a lot

 

[Communicator]

Looking at the photos, you do not have the immobiliser as fitted to later x230 models. The item "MaybeTheImmobiliser", appears to be a solenoid valve, and could be an aftermarket security device. It may be difficult to remove because there seem to be hose barbs on the metal connecting pipes. If it is a solenoid valve can you trace the supply cable? The central Phillips #2? screw probably is a fixing for a dedicated connector. I remember viewing something similar in a paper catalogue many years ago.

 

[RalphM]

Before going any further I would try a new fuel cap, the cap on a Panda as the breather built in I suspect
yours is the same.

 

[Daka]

Hi @Communicator , hi @RalphM, thanks a lot for your support! After 2 weekend trips without any problems the problem unfortunately occurred again today: The motor went out 3 times, always within the first 5min of driving. The fuel cap was super loose. I find it weird that after the car has driven for a while, the problem does not occur again. Anyone with an idea why that is? Does this indicate to a problem with the immobiliser? Unfortunately I did not succeed in finding a manual to remove the specific immobilizer we have.

 

[Daka]

@Communicator: yes, it seems to be a solenoid valve. I traced the cable. It leads to the upper right area where the diesel filter is and enters the driver's cabin there. What is the central Phillips #2 screw?

 

[Communicator]

@Communicator: yes, it seems to be a solenoid valve. I traced the cable. It leads to the upper right area where the diesel filter is and enters the driver's cabin there. What is the central Phillips #2 screw?

Nothing special. On your photo titled "MaybeTheImmobiliser", roughly on vertical centre and about 25% from bottom, cross headed screw, probably retaining solenoid valve electrical connector. Since this valve seems to be an after market device, I am wondering if the supply is not soundly connected and via what? A loose connection in the supply to the valve, could be the cause your problem. Another thought is the the solenoid valve is sticking, and only partly opening on some occasions. This could lead to fuel starvation.

 

[RalphM]

Immobilisers are designed in such a way that once started they will not stop
the engine until you switch off the ignition, otherwise a immobiliser failure
could quite easily dump you anywhere inc the fast lane of the M1, I don't
think its the immobiliser.

If the immobiliser is just a solenoid it is possible that the solenoid is getting
lazy and not fully opening, after 2 or 3 stops things get warm and vibration
allows it to open fully and it's fine till the next time.

Maybe worth a try turning the ignition on and off 3 or 4 times then starting it in the hope that it forces a sticking valve to open fully

 

[Communicator]

Immobilisers are designed in such a way that once started they will not stop
the engine until you switch off the ignition, otherwise a immobiliser failure
could quite easily dump you anywhere inc the fast lane of the M1, I don't
think its the immobiliser.

If the immobiliser is just a solenoid it is possible that the solenoid is getting
lazy and not fully opening, after 2 or 3 stops things get warm and vibration
allows it to open fully and it's fine till the next time.

Maybe worth a try turning the ignition on and off 3 or 4 times then starting it in the hope that it forces a sticking valve to open fully

This agrees with my final sentence above. So is that two votes against the solenoid?

 

[RalphM]

It could still be the solenoid the immobiliser could be powering it up but if it’s sticking or lazy it could still be the solenoid

 

[Communicator]

It could still be the solenoid the immobiliser could be powering it up but if it’s sticking or lazy it could still be the solenoid

Perhaps you misunderstood. We are in agreement as regards the sticking solenoid being a possibility.

 

[RalphM]

Yes I must have missed something.