Black soot around exhaust and smoke on acceleration

[CagaA4]

I have a 2010 2.0 CAGA engine A4 which has heavy black smoke on acceleration and a rough idle on cold start and down on power in 2nd / 3rd while it's piling smoke out the back.

It's recently had a new cambelt, fuel injectors, fuel filter, MAF and air filter.

The car has zero DTC codes in VCDS, EGR / turbo / intake / 02 sensors test fine in VCDS and physically EGR is clean also the DPF is at 5 grams of soot.

The car doesn't use any coolant or oil whatsoever and does 600 miles on a tank.

I'm running out of ideas on what might be the cause.

 

[spartacus 68]

I was going to reply as it points to injectors, but you say they’ve been replaced. If you’re getting soot and smoke then it’s fuel related in terms of potentially too much fuel, or air is getting in and affecting something.

You also say EGR is physically clean? Did you use new gaskets when refitting? I’d have thought a sensor would have picked up on this by now and thrown an error code especially with it running rough.

Prior to the cambelt change how was it running? Definitely not a tooth out?

Any issues I’ve ever had diesel related to do with emissions, and this is going back a bit to my old 80 TDI Avant, then I used to put Forte diesel conditioner in it and boot it. Used to smoke like frigate through the gears for 2-3 minutes then ran sweet as a nut.

I’m in the middle of replacing the turbo on my Allroad. Might be worth stripping yours out and checking the vacuum on the actuator and the variable vanes on the turbo for movement. Will just cost you a fitting kit assuming everything is within tolerance and no play on the turbines. Good opportunity to clean the turbo until it’s spotless.

 

[EXSpartan36]

If all this has happened after all the work has been done I would be getting that checked.

Black smoke is usually lack of air or too much fuel. Check your intercooler isn't split and check all your pipe work isn't split between intake manifold and turbo.