AFN Engine Torque Dip at 2000 RPM

Hello everyone,

I took my Ibiza 6K AFN to the dynamometer today. It was a dynamometer test with a brake.
I suspected that the performance wasn't quite right, as it was struggling to reach the top speed of 200 km/h. Compared to a Golf III AFN, it's officially registered with 5 km/h more top speed.
'Additionally, I'm still experiencing the problem where the engine is very slow to respond. When I press the accelerator at 3000 RPM, it takes almost a full second before I get full torque.'
Attached is the image from the test run. The torque dip is clearly visible.
What could that be?

'Thank you very much!!!'
Martin.

Martin L. wrote:

Hello everyone, "Furthermore, I'm still experiencing the problem where the engine is very slow to respond. If I press the accelerator at 3000 RPM, it takes almost a full second before I get full torque." Attached is the image from the test run. The torque dip is clearly visible. What could that be?

Hi Martin,

I'm initially suspecting a jammed VTG (Variable Transmission Gear).

A diagnostic trip using VAGCOM, or even just having an OBD adapter on board, can provide clarity...

Thank you very much!
You're absolutely right, the LDA definitely needs to be included.
When I touch the control linkage of the VTG (Variable Turbine Geometry) during engine start, it pulls about 10-15mm. However, it takes about 3 seconds for it to pull. The movement is quite fast.
Is it because the vacuum pump first needs to build up the vacuum? When I look at the power consumption of the BKV (boost control valve), I see that there is still some vacuum present for a certain time after the engine is turned off. But even so, the VTG (variable turbine geometry) doesn't adjust until after a delay.

Hi fellow namesake.

You can usually tell if a VTG (Variable Turbine Geometry) shaft is stuck by the "erratic" behavior of the control valve (N75) during operation.

Perhaps the rod is stuck in a certain position, and at 2000 RPM under load (i.e., while driving), you certainly wouldn't have your hand on the rod .

Log measurement group 011 – that will clearly show what the VTG is doing.

m;

Hello there,

Okay, if I look at the torque curve and compare it to my experience with my AFN engine in my Passat from 1999, then you must have been testing my car on the dynamometer.
However, I expect to see a more significant drop at 2800.

I've been experiencing this issue for about 2 years now. The rod on the loader is moving freely, and the vacuum hoses also seem to be in good condition.

I also assume that if this is related to a stuck or malfunctioning load leveler, it shouldn't remain in that state for more than 2 years!??

Okay, I'm definitely interested in changing my behavior.

Christoph.

Also, to you too, Christof.

Log something while you're driving - you sometimes see interesting things .

m;