Hi Simon,
Strange that it should occur after a period of time stuck in traffic idling. Maybe its fuel related. Have you changed the diesel filter recently? This would be my first point to address.

Secondly I would be looking toward the camshaft sensor, it sits on the back top of the rocker cover and gets some real abuse from temperature extremes. iIs more likely to go faulty when it gets hot. This would be my second stab in the dark. Obviously a code read with a good MB compatible reader would be the best starting place as its ‘parts darts’ without this info.

Check out the brake light switch above the the pedal, make sure its working with a test meter. Its a dual switch one side operates the brake lamps the other tells the ECU brakes are being applied – common problem and a cheap fix.

It goes without saying turbo boost leaks are the most common cause of limp-home activation and you should check in the hard to see places such as the connections to the intercooler where oil staining will be the giveaway there is a leak, if its all clean and tidy then it is generally leak free. The big hose that goes to the inlet manifold splits underneath where you cant see it, remove the hose and flex it all over and look for cracks/splits.

Let me now how you get on.

All the best Steve

Hi Dunk,
I suppose because its such a dirty job and time consuming I have never taken pictures as I have worked and to be honest they tell the story a lot better than the written word. As your vehicle is a 2004 W639 rear wheel drive the power plant is the same as a 4 cylinder sprinter and there is this excellent article here that should give you all the pointers you need, just imagine its on a Vito and accept there will be some minor differences to ancillaries and pipework, but in general you should be go to go with this.

http://sprintervanconversion.weebly.com/cylinder-head-removal.html

Thanks for the positive comments, I hope this helps you out.

All the best Steve

Hi There,
Assuming that there is no diesel leaking from the recut seals and all is fine, tight and dry then I would check out the electrical connectors to the injectors, make sure they are fully home and clicked in, if the tabs have been broken use tie wraps to hold the plugs in tight. Each injector is ‘classified’ or calibrated by a dealer diagnostic tool, to each cylinder so you may expect some running issues. In my own experience, this is only a ‘fine tuning’ and to be honest the engine should run 80-90 per cent good, if its rough and very poor look for other related troubles.

When the injectors were removed from the head, did they use a slide hammer tool to remove them that screw fits on the inside of the injector? With these you have to remove the injector solenoid, there is a danger if this is done that parts are dislodged or lost (small ball bearings etc) from the solenoid mechanism of the injector. If of course the heads of the units have not been disturbed – discount this. Look for damage to the wiring in the loom on the head by the injector rail, especially to the camshaft sensor on the rocker cover rear as this can get pinched if care is not taken when removing the rearward injector.

I hope this helps you out in some way.

All the best
Steve

some great advice there steve ! I had a similar problem and i had to change the injector pump

regarding the mileage – the ecu has clearly been clocked. i suggest you get advice form the police / governing body / solicitor. you may able to get some money back and hopefully it will pay for a new pump

Steve where is your workshop based / called ?

Hi Craig,
Seems you have some difficulties to overcome!
My first feelings regarding the fuel pressure issue when warm (if they have in fact measured the rail pressure) would be:
If the problems are in low pressure fuel delivery:
Fuel delivery pressure sensor, this lies on the right hand side front (looking into the engine bay) pointing down, just below the intake manifold on the block, Tee’d into the low pressure fuel line. (You may have had this changed but from the description its a little difficult to be sure)
If its high pressure the most common problem would have been the rail pressure regulator but it reads from your description that this has been swapped so discount that. There is a chance that if the HP rail pressure is actually dropping it may be the high pressure pump that is giving trouble when warm. Having re-sealed a couple of these that were leaking they are high tolerance devices and do wear, I can only imagine that maybe the internal components are worn not allowing full pressure once temperature has risen. This is the triangular pump on the front of the engine. A diesel specialist will be able to test this out for you, or maybe purchase a used good one for about £70 to £100 dependant on age. I feel having gone this far and pretty much discounted most of the common stuff the High pressure pump would be next on the list. The EML lamp does not always illuminate, it all depends on the level of fault, I am sure if the fuel pressure returned to normal the ECU would reset the LHM on next key operation.

See here for a bit of background, makes interesting reading, look specifically in the paragraph regarding faulty HP diesel pump.

http://www.dieseljones.co.uk/troubleshoot-a-diesel-engine.html

The ECU does record miles/kms internally and also does the speedo pod, changing one does not change the other, its a specialist job to change the recorded miles on either so really unlikely if you have a service history to back up the claimed mileage. What may have happened is that the ECU is faulty and the recorded internal odo reading is screwed. This is further backed up by the inability of the STAR to read/clear the ECU – Indeed if anything can read it this should! Of course there is a chance just as the miles are reading incorrectly that the signal from the fuel rail is being interpreted incorrectly by a faulty ECU and giving rise to the problem you see.

The ECU works in conjunction with the DAS module (Driver authorisation system) that lives behind the speedo binnacle/inside the column. If you could get this module, its matching key and main ECU you could swap the whole thing and see if any improvement was seen. The dealership have the ability to program a new ECU to your existing DAS and this would be the cheapest method, and you would be sure the ECU was of the correct type for the vehicle.

All in all a very unfortunate set of circumstances that I hope they will soon get to the bottom of.

Do let me know how you get on.
All the best
Steve

Could not have said it better myself, thanks Gary.
All the best
Steve

Useful info as always, cheers Vic.
Best Regards
Steve

Hi there,
If you have problems with the gearbox internals currently, then you could really ask the same question of the existing oil and current mechanical condition – so that really is a bit of a mute point. The thing is, if you can improve the situation then all well and good, the oil is gearbox rated and fully synthetic so should be at least on par as what is installed currently. I have now done appx 20,000 miles now and no ill effects. Its worth a shot. If you save the old oil you can always put it back in if there is no improvement and you feel more comfortable by doing that.
Give it a go!
All the best Steve

Hi Bob,
First inclination is that the turbo actuator vacuum is being effected/starved when you use the AC, thus not then functioning correctly (pulling the turbo actuator rod ineffectively). This is most likely a physical vac leak, split pipe or faulty reserve sphere (next to air box) The AC will draw some vac to operate the internal flaps inside the cabin etc, if the supply pipework to this or other related components is faulty then there will be a degree of vac loss/leakage. This could have an effect on the vac available at the turbo actuator, causing limp home (no turbo boost) this condition would NOT necessarily cause the dash MIL lamp to light. If the vehicle is otherwise mostly trouble-free then look here first.

The auto gearbox will also cause limp home, but possibly with a combination of locking the gearbox into one ‘safe’ gear to prevent transmission damage. If you have had this competently repaired, then this I doubt will be the root cause of the on going power loss problem (which you have had all along) – this issue is caused by the transmission ECU ‘locking down’ the gearbox and limping the engine in a safe mode, this would normally give you a dash indication on the MIL lamp.

I hope this gives you some pointers and its at least a little help to a painful intermittent problem. Let me know how you get on.

All the best Steve

Thanks for the comment, glad it worked out.
All the best
Steve

Hi there Joe,
Fuel pressure related fault, I would replace the fuel filter first. If still no change look for problems in the wiring loom to the engine, especially look where the loom branches from the block to the inner engine bay, could be a short or problem of some sort in that region. You would be best to get a code read with some form of live-data display so you can be more specific where the fault lies as this code is a generic code and non specific for fuel pressure related problems. Filter swap first.

All the best Steve