Delayed Gas Acceptance

Hello everyone!

I was able to observe the following:

Polo Caddy, 1.9 SDI engine, stops running after a long period of full acceleration, even if you briefly release the accelerator pedal. This Caddy is my company car.

Okay, so I pushed my T4 (ACV) a bit, not full throttle, but still quite fast, and the same thing happened. It only occurred once.

No error codes were found in the diagnostic memory of either vehicle.

What could that be ?

Greetings, Peter.

"ARG is a possibility, I think. Otherwise... I have no idea."

You probably mean the AGR, right? Well, since the Caddy doesn't have an AGR because SDI is rather impossible.

Regarding the T4, I would also tend to rule that out, because when the clutch was depressed, no throttle was applied. With a stuck AGR valve, at least the engine speed would increase when the clutch is depressed.

As I mentioned, there are no error codes registered in the diagnostic memory for either vehicle.

Best regards, Peter.

Postscript: P.S.: Correction, see below!!!!

Hello!

The topic interests me because I'm currently experiencing a similar problem (or, I'd say, a very similar one) with my A6 2.5.

The engine then starts to accelerate, but it only runs on a few cylinders, and the entire drivetrain vibrates.

Is it the same for you?

Regards,

Knubbi.

Okay, here's the translation:

'Just a random question: Why doesn't the SDI have AGR?'

Absolutely correct objection. Of course, the SDI has an AGR (Abgasrückführung system). Unfortunately, due to a typo in the previous post, I mistakenly associated it with VTG (variable turbine geometry), sorry, my fault.

However, it must be added that in my T4, the EGR valve is blocked, "...something once fell into it, I think a piece of metal..."

That's why I'm so surprised by all of this. Two different engines exhibiting the same behavior. A thorough visual inspection of the vacuum system, including connectors, cables, and other potentially relevant parts, revealed nothing.

Is it possible that one of the vacuum system's solenoid valves is causing this problem? But why isn't the engine responding to the throttle at all? Also, the RPM doesn't increase even when the clutch is depressed.

Best regards, Peter.

Peter!

Have you made any progress with your problem?

What error codes are stored in your system?

Possibly a problem with the accelerator pedal sensor.

Regards,

Knubbi.

Hello!

"No, unfortunately, I haven't made any progress yet. Surprisingly, there's no error code stored in the system. The problem didn't reappear in my T4 either. In the Caddy, it occurs sporadically."

Greetings, Peter.

So, I believe that the problem with my A6 2.5 is the EGR valve.

I'll disable it tomorrow with a metal sheet.

My car has the same symptoms.

Well, I'm curious to see. Mine has a defective AGR valve too, you know, a piece of metal fell inside. The symptoms are exactly the same.

Best regards, Peter.