TDI AMF 1.4: Full Throttle Tuning

Hello.

"Recently, I've been experiencing a phenomenon where, under full load, and not always consistently, but seemingly more often on steep inclines and when taking fast corners around 3800 RPM, the engine momentarily stops responding to the throttle for a fraction of a second, then immediately resumes pulling. It feels like the throttle is suddenly released and then immediately pressed again. I'm also noticing symptoms that suggest a failing throttle pedal."

The accelerator pedal must be fully depressed, or preferably almost fully depressed.

Fuel level is irrelevant.

The error memory is empty. The accelerator pedal was replaced a few months ago due to a defect (used part).

Laufleistung: 260000 km, 220000 mit Chip. Seit ca. 120000 km mit langem 5. Gang.

Does anyone have a suggestion?

I bought new fuel filters once, but it's a bit too cold to change them right now (the check valve tends to break off).
Furthermore, the error cannot be reproduced in the north because it lacks the steep inclines and tight curves that would allow one to safely drive at speeds exceeding 170 km/h. The issue is practically impossible to reproduce in lower gears.

In my experience, a deviation in the throttle pedal position sensors would generate an entry in the error memory.

Thank you for the tips.

Hi,

Brake light switch?

Best regards,

PD connection strips...they have a similar effect!

Gremlin wrote:

Hi, Brake light switch? Regards

A good idea would be to simply log measurement block 6 in the engine control unit using VCDS (of course, without engaging the clutch or brakes).

The original switch can be easily readjusted by hand, so I would try that first: press the pedal and pull out the switch pin with the knob on it.
Does it automatically adjust when you release or press the pedal?

However, the accessories also include switches that need to be manually adjusted.

Best regards, Rainer.

Okay, I'll take a look at the individual points soon.

Are there any critical points on the connection rail of the PD elements that are easy to find? I've never worked with them before, so please excuse my potentially naive questions.

"Is a photo available?" or "Is there a photo?"

Olaf wrote:

Are there any critical points on the connection rail of the PD elements that are easy to find?

I've never worked on them before, so please excuse the silly questions. }Common search terms: PDE wiring harness, etc.
AFAIK, the contact pressures of the PDE-side connectors are decreasing, which can result in intermittent contact issues that resemble loose connections. The cause is likely material fatigue, and in that case, replacing the entire wiring harness is the best and not overly expensive solution.

Is the voltage supply relay of the control unit faulty?

Quote:

Recently, I've noticed a phenomenon where, under full load, not really reproducible but apparently occurring more often on steep inclines and fast-driven curves around 3800 RPM, the engine momentarily doesn't respond to the throttle for a fraction of a second, but then immediately pulls again. It feels like suddenly releasing the throttle and immediately pressing it again.

Never or rarely?

Only on straight roads with steep inclines, and very rarely (maybe twice so far).
Unfortunately, it's not really reproducible.

It behaves like a faulty accelerator pedal with implausible potentiometer values. However, when it really started acting up, it also showed up in the error memory.

Oh yeah, on the day when this problem first occurred, a new battery had been installed (with the same capacity) because the old one was finally dead after over 12 years and couldn't handle the cold anymore.

P.S.
The cart is working properly again, so I haven't had a chance to look into it further.
Brake pedal switch is OK.