Technical Ducato 2.8JTD power loss

[Anthony489]

Hi

The rattle (oscillaton) will occur when you have a resonant mechanical system (i.e. a spring and a mass) and it is excited in some way, in this case by the gas pressure under certain conditions. If there is a bit of friction in the system it will tend to dampen the oscillation, which is good. Not too much friction though, or the actuator will not be able to move it properly. Any free play (maybe a little bit of wear in the spindle bush) will tend to increase oscillation. Light lubricant like WD40 may reduce the friction, which is maybe not what you want. On the other hand, if there is drag from heavy grease this will dampen the oscillation, which is useful. I am not sure if there is a type of grease which can withstand the high temperatures and still be heavy (viscous) enough to give damping in the long term.

Some people have cured the noise by fitting a small coil spring to pull the actuating lever sideways. Maybe this compensates for the play in the spindle bush, by keeping the spindle biased to one side of the bush where it will have metal-on-metal friction ?

I cannot see how the oscillation/rattle can affect the average boost by very much, unless the movement is quite large. Only a small video camera and monitor would let you see it while driving.

Thinking about other causes, your symptoms suggest something that comes and goes. This is typical of poor electrical contacts, which are sensitive to heat and vibration. Without seeing your van, I cannot suggest where to look but I agree the injectors would be a good start as they draw high peak currents so are sensitive to poor connections. This is a bit surprising, as the pictures and videos of your van show it to be very clean underneath and suggest it has been kept indoors most of its life !

The throttle pedal normally has two potentiometers with separate wires back to the ECU. The ECU compares the signals from the potentiometers, to make sure they are the same (or almost the same). If they are too different, it will store an error code but may still allow driving.

 

[corsedanny]

Hi

The rattle (oscillaton) will occur when you have a resonant mechanical system (i.e. a spring and a mass) and it is excited in some way, in this case by the gas pressure under certain conditions. If there is a bit of friction in the system it will tend to dampen the oscillation, which is good. Not too much friction though, or the actuator will not be able to move it properly. Any free play (maybe a little bit of wear in the spindle bush) will tend to increase oscillation. Light lubricant like WD40 may reduce the friction, which is maybe not what you want. On the other hand, if there is drag from heavy grease this will dampen the oscillation, which is useful. I am not sure if there is a type of grease which can withstand the high temperatures and still be heavy (viscous) enough to give damping in the long term.

Some people have cured the noise by fitting a small coil spring to pull the actuating lever sideways. Maybe this compensates for the play in the spindle bush, by keeping the spindle biased to one side of the bush where it will have metal-on-metal friction ?

I cannot see how the oscillation/rattle can affect the average boost by very much, unless the movement is quite large. Only a small video camera and monitor would let you see it while driving.

Thinking about other causes, your symptoms suggest something that comes and goes. This is typical of poor electrical contacts, which are sensitive to heat and vibration. Without seeing your van, I cannot suggest where to look but I agree the injectors would be a good start as they draw high peak currents so are sensitive to poor connections. This is a bit surprising, as the pictures and videos of your van show it to be very clean underneath and suggest it has been kept indoors most of its life !

The throttle pedal normally has two potentiometers with separate wires back to the ECU. The ECU compares the signals from the potentiometers, to make sure they are the same (or almost the same). If they are too different, it will store an error code but may still allow driving.

Thanks for your welcome feedback Anthony!

Yesterday i found information regarding, indeed, an electronical issue between injection control unit and throttle pedal.. today i removed a certain connector and put all wires together.. its good and tight, but not on the nicest way as i cant solder here. Started the car and worked, but cant drive atm so couldnt really test this yet. It comes from the Netherlands this information, specifically the id number of the vehicle starting with a certain number has this issue (which includes mine), on that forum literally everyone got their problem solved. The only thing is that i havent seen my injection warning light going on at the dash. Which most others did have.

The forum is in Dutch, but i am willing to share the link if you want. If this turns out to be helpfull, i will post a guide of how to do this here, for future cases so people know what to try .

 

[corsedanny]

Small update from my side.

I have deinstalled a certain connector between the throttle pedal potentiometer going to the injection control unit.. yesterday evening (colder air temps) i did a testdrive and yes i did have turbo power back!

I will, for those with x230 Ducatos, make a short manual of what to do when you experience these problems and for sure when you have your injector wqrning light coming on.

So a big step forward seems to be made. With cold engine though, i have quite a bit of Turbo whine going on and i am also not yet satisfied with how smoothly the engine is operating. This can still be improved.

I wonder if anybody knows whether i have the old injector connectors or the ones that were built in as a replacement. Hope anybody knows this..