Grey smoke

Greetings to all,

I'm a new member here and this is my first post although I've been reading topics here for quite a while. I'm driving a Mk4 Golf with the AHF engine, recently I had a turbo failure and decided to additionally up the power a bit because I was running a simple tune before that. Now the car has a GTB2056VL turbo, 0.280 um DSSR nozzles, 11 mm Bosch pump element with the stock cam plate, ASZ intake and air filter Box, Toyosports FMIC and so on. Due to the stock exhaust and SMF clutch it's peaking at 1.7 bar atm with a smooth power delivery.

Anyway the problem is as follows - when I start the car cold it smokes pretty bad, smells like unburnt diesel. Even idling for a few minutes it doesn't stop. When it reaches operating temperature it's better, but can still be noticed. I had my GF drive infront of me yesterday and saw that it smokes when given a bit of a throttle to accelerate. Oil level is constant, glow plugs have been checked and timing is at the top of the graph at the yellow line. I had the tuner decrease the amount of fuel at idling and the car is really sluggish around 1k rpms but to no avail. Should I check compression for a bent rod or its something tune related and I should look for another tuner once I make a proper downpipe and firlt the 6 speed gearbox.


Thanks in advance.

more timing advance might clear it up (the graph you speak of actually means absolutely nothing), but it's probably a leaking injector

It's the timing graph in VCDS, sorry. Before putting them in the car the machanic said that he tested the injectors and they were fine. DSSR nozzles in the stock injectors.

deviant said:

It's the timing graph in VCDS, sorry.

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yup, means nothing

Black smoke= diesel fuel thats unburnt, but scorched, from lack of oxygen to complete combustion of all the fuel, grey usually means lack of combustion chamber temperature due to cold ambient temps/engine temps, or, lack of compression, fuel that hasn't been scorched. X2 486, perhaps advance timing a bit. Do you know that timing values are?

After what tune/upgrade this problem game?

It can be clogged fuel filter, leaking nozzles, bent rods, bad timing...

Do you have VCDS?

Well after the turbo went, we put all the stuff at once. I have VCDS. Fuel filter is a brand new unit. Some people with build TDIs told me its normal during the winter, but still.

How much did you rise nozzle opening pressure?

Give us some logs from group 004, 015 and 013 (just for fun)

Thanks everyone for the responses. Just an update - the car got wrecked. Some chick decided she'd turn left in front of me at the light and car is totaled.

deviant said:

Thanks everyone for the responses. Just an update - the car got wrecked. Some chick decided she'd turn left in front of me at the light and car is totaled.

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Sorry to hear about the accident but I hope you are ok and no damage to the body. The car can be replaced.