Combo 1.3cdti van, 2010 model, 90,000 miles.
The symptom is a bout of uneven running when feathering in the throttle below 1000rpm, i.e. trailing throttle approaching a turn into a side street, when gently accelerating out of the bend I get the kangaroo juice....regularly, but not every time. I alleviate the problem by coming back off the throttle briefly and trying again, or by dipping the clutch and taking the revs above 1000rpm.
There are no stored fault codes.
The problem does not seem to occur when using heavy throttle rather than light throttle.
The problem does not seem to occur any more or any less frequent when the engine is hot or cold.
Any ideas?
For my information: What is the control strategy for the EGR valve? i.e. when is it commanded to open, and when is it commanded shut? Does it have proportional control (eg 25% open, 80% open)?
What is the minimum fuel pressure for the injectors to work properly? Is there a fuel pressure relief valve to prevent overpressure when on a trailing throttle (and the injectors are shut off)?
My own viewpoint is that the EGR valve may be sticking open, causing the oxygen level to fall too far to burn the fuel properly....that is if it has been commanded open on the trailing throttle (see question above about EGR control). Alternatively, if there IS a fuel pressure relief valve AND that is re-seating poorly, then it might be that there is insufficient fuel pressure below 1000rpm to fire all the injectors properly.
I await more learned and experienced opinion.
MM
The symptom is a bout of uneven running when feathering in the throttle below 1000rpm, i.e. trailing throttle approaching a turn into a side street, when gently accelerating out of the bend I get the kangaroo juice....regularly, but not every time. I alleviate the problem by coming back off the throttle briefly and trying again, or by dipping the clutch and taking the revs above 1000rpm.
There are no stored fault codes.
The problem does not seem to occur when using heavy throttle rather than light throttle.
The problem does not seem to occur any more or any less frequent when the engine is hot or cold.
Any ideas?
For my information: What is the control strategy for the EGR valve? i.e. when is it commanded to open, and when is it commanded shut? Does it have proportional control (eg 25% open, 80% open)?
What is the minimum fuel pressure for the injectors to work properly? Is there a fuel pressure relief valve to prevent overpressure when on a trailing throttle (and the injectors are shut off)?
My own viewpoint is that the EGR valve may be sticking open, causing the oxygen level to fall too far to burn the fuel properly....that is if it has been commanded open on the trailing throttle (see question above about EGR control). Alternatively, if there IS a fuel pressure relief valve AND that is re-seating poorly, then it might be that there is insufficient fuel pressure below 1000rpm to fire all the injectors properly.
I await more learned and experienced opinion.
MM
