Hi all,

Long one here...

Picked up a 2009 mk2.5 Focus 1.8tdci, and it's running atrociously rich on acceleration. If I pull away below about 1200rpm, I slowly build revs to about 2000 and then hit a wall where it won't rev any further, all the while throwing out a white cloud of diesel behind me, and my fuel economy reading 30-40L/100km. It does this more often when cold.

 If I keep my foot down I still don't accelerate, but after a few seconds I get an engine malfunction message on the dash, and a p010f MAF code. I have tried running with a disconnected maf, but the symptoms still appear.

 If I let off the throttle and then come back on, it accelerates again, but not as quickly as this car should. 

If I pull away at 2000rpm and let out the clutch slowly, it pulls away better, but the turbo doesn't do anything until nearly 3000 (peak torque should be 1800rpm on this), and then it kicks in hard to what feels like a normal level, but it still smokes (still white).

Turbo seems to be noiser than it should be (can hear it spin up a lot louder than normal), and if I let off throttle I sometimes get turbo flutter. It's an electronically controlled Variable Geometry Turbo.

I have checked for boost leaks but can't find any. No split hoses, no bubbles from soapy water, nada. I do hear a faint whistle/hiss if I'm crusing at around 2000rpm with hardly any throttle input, but I can't find the source, as it won't do it while stationary. It stops immediately if I let off throttle, and is lower pitch the less throttle is applied. Past about 5% pedal travel, it doesn't get any louder or change pitch. It seems to carry on to higher revs, but doesn't get any louder so gets drowned out around 3000-3500RPM

If I rev it in neutral, I deploy a black smokescreen behind the car, and leave a sooty skidmark under the exhaust pipe.

The only persistent code I get is a p0490 EGR Circuit High, but the EGR is blanked with a stainless blank and gaskets, and I have checked the EGR itself and the spindle moves stop to stop with no issues, and the actuator moves and reacts to throttle input when I have it separated from the EGR.

Watching the readouts while I drive, it reacts exactly as expected to throttle inputs. The position sensor matches the PWM signal almost exactly, except when it throws an error the position sensor drops to reading it as closed, while the PWM signal to it is still commanding open. If I reset the code, it could be days or weeks before it comes back.

At highway speeds the fuel economy is perfect (5L/100km), but around town, even when warm, it's abysmal.

Please god help me...

TLDR;
Car smokes white when accelerating, but not burning coolant or oil.
Smokes black when revved in neutral.
Worse when cold.
Doesn't seem to be a boost leak.
Sometimes won't rev past 2000RPM unless I let off the throttle and try again.
If I don't let off, it throws a MAF code, but removing MAF made no difference, and even after the code, if I let off the throttle and try again, it accelerates
Has been getting worse over the last few weeks.
Slight whistle/hiss on throttle, but not very loud.
Diesel mileage is awful except when doing constant speed/constant load.

Sorry I can’t help but at least you don’t have a dpf

Hi Simon, did you ever get to the bottom of this please? I am having a similar problem