VW group 1.4 PD turbo diesel - heavy smoke under load

[Jaguar steve]

Pretty much as the title.

Engine in a Skoda Roomster which runs well and performs as expected but leaves a black smokescreen James Bond would be proud of when on full throttle and boost and exhaust is thick with soot. No codes on OBD scan.

So far I've stripped and cleaned the EGR valve which was filthy, air filter is new and I can't see or hear any leaks on the turbo pipework.

Any ideas Chaps? MAF sensor?

[bearman68]

Injectors are clearly overfueling for the air flow - so on the injection side, leaking or otherwise duff injectors, issues with the control of the injectors - MAF, turbo boost sensor etc, issues with the turbo - actuator / adjustment incorrect, boost pressure solenoid stuck open. or the NRV clogged up and dirty. Finally, I have seen them with a blocked exhaust. Or the ECU could be duff.
For me, I would use VCDS to plot boost pressure v actual, to understand the turbo performance first.

[PositronicRay]

Hasn't had a dodgy map has it?

[Jaguar steve]

bearman68 said:

Injectors are clearly overfueling for the air flow - so on the injection side, leaking or otherwise duff injectors, issues with the control of the injectors - MAF, turbo boost sensor etc, issues with the turbo - actuator / adjustment incorrect, boost pressure solenoid stuck open. or the NRV clogged up and dirty. Finally, I have seen them with a blocked exhaust. Or the ECU could be duff.
For me, I would use VCDS to plot boost pressure v actual, to understand the turbo performance first.

Thanks for that Done 82k with very FSH and a 0.41 (m-1) MOT gas analysis about 5k ago

VCDS? NRV? Is this time to make some calls?

[Jaguar steve]

PositronicRay said:

Hasn't had a dodgy map has it?

Nope - not as far as I know. Comes from a good home as far as I can tell and... Really? whose gonna remap a bloody Roomster?

[bearman68]

Jaguar steve said:

Thanks for that Done 82k with very FSH and a 0.41 (m-1) MOT gas analysis about 5k ago

VCDS? NRV? Is this time to make some calls?

VCDS = Vag Com diagnostic system. Cheap as chips system for VAG stuff, and quite powerful. Measuring group 12 (IIRC) shows desired turbo pressure and actual, and can be graphed while driving the car, and is a very powerful tool for turbo investigations.
NRV = Non return valve. There is a small filter in the vac system line, and this blocks up. It maintains the turbo actuator position resulting in pressure errors. (Trace the vac line from the back of the turbo actuator) - you''ll find it eventually.
Whereabouts are you?

[Jaguar steve]

bearman68 said:

Jaguar steve said:

Thanks for that Done 82k with very FSH and a 0.41 (m-1) MOT gas analysis about 5k ago

VCDS? NRV? Is this time to make some calls?

VCDS = Vag Com diagnostic system. Cheap as chips system for VAG stuff, and quite powerful. Measuring group 12 (IIRC) shows desired turbo pressure and actual, and can be graphed while driving the car, and is a very powerful tool for turbo investigations.
NRV = Non return valve. There is a small filter in the vac system line, and this blocks up. It maintains the turbo actuator position resulting in pressure errors. (Trace the vac line from the back of the turbo actuator) - you''ll find it eventually.
Whereabouts are you?

Essex Badlands / Sufolk borders.

Turbo actuator? Is that the bit next to the EGR valve with the diaphragm and vac line on top? That was quite clagged up too and I've done all I can in there with a scraper and vacuum cleaner when I had the EGR valve off.

Will have another nosey around tomorrow - bit out of my comfort zone on this one so ta very muchly

[Mignon]

blocked fuel filter can cause smoke

[Jaguar steve]

Into the garage tomorrow morning. Will post whats broken on it. Cheers Chaps