Motor-Stop-Verhalten bei Deaktivierung AGR Saugrohrklappe | Posts 16+

Quote:

1. AGR valve with integrated vacuum control valve, controlled via a solenoid valve. 2. Similar to the first, but additionally featuring a throttle valve in the intake manifold, controlled pneumatically or via an electric actuator. 3. Similar to 2, but with a water-cooled exhaust pipe leading to the collection pipe.

Not quite, or what?

1. as in 1Z AFN.
2. (pneumatic only!!) (all G4 TDIs - until recently)
3. It wasn't until the regulated cooling system was introduced that the E-flap was also implemented (e.g., in the new AXR engine).

Here's my latest update.

m;

(Please correct or supplement me):

1. AGR valve with integrated vacuum control valve, controlled via a solenoid valve.
2. Similar to the first, but additionally featuring a throttle valve in the intake manifold, controlled pneumatically or via an electric actuator.
3. Similar to item 2, but with a water-cooled exhaust pipe leading to the collection manifold.


You need to distinguish between a throttle valve and a shut-off valve. These are two completely different things!

The shut-off valve is CLOSED (and truly ONLY closed) when the engine is stopped to prevent backflow.

The throttle valves are closed in a controlled manner to create a vacuum downstream of the valve, which increases the EGR rate. Since the throttle valve directly affects the EGR rate, it must be diagnosable according to the EOBD standard. Furthermore, the ability to move it electrically increases the precision and speed of control.

Therefore, my ALH engine has a water-cooled EGR (with the cooler constantly in operation) and a shut-off valve. The ALH engine with a manual transmission (like all other VP-TDI engines in its series) has an uncooled EGR with a shut-off valve. The EGR connection is the same for these engines.

So far, we have 7 possibilities.
1. AGR pure.
2. AGR with AK.
3. AGR with WK and AK.
4. AGR with DK.
5. AGR with WK and DK.
6. AGR mit gereg. WK and AK.
7. AGR mit gereg. WK and DK.
(WK = water cooling, DK = throttle valve, AK = shut-off valve)

1 older TDI.
2, basically all the newer TDI models.
3 automatic versions: ASV and ALH (possibly others).
4 SDI (if I recall correctly).
5. I don't know any.
6. Unknown to me.
7, for example, Bertils AXR, and probably all newer Euro 4 models.


Following the excursion into the world of AGR systems, here's the question posed at the beginning again:
What specific experiences have you had with the behavior of the vehicle when the AGR (Exhaust Gas Recirculation) or the throttle valve is deactivated?


The sudden stop is back, and sometimes it's quite abrupt...
'With an active shut-off valve, the machine shuts down smoothly. Since I only have one shut-off valve... why would I permanently decommission it?'

CU Gremlin.

Hi Gremlin,

If I understand you correctly, you're referring to two separate valves in terms of their physical design. Until now, I've believed that the throttle valve also serves as the shut-off valve, because in the various TDI models, I've only ever found one (throttle) valve in the intake manifold, whether controlled electronically or pneumatically via a control valve. I'm not talking about the actual EGR valve (which is fundamentally pneumatically controlled), which is not designed as a valve and separates the exhaust side from the intake manifold.

Regards,

Sepp.

Gremlin wrote:

.... 7. AGR mit gereg. WK and DK. (WK = water cooling, DK = throttle valve, AK = shut-off valve) ... 7, for example, Bertils AXR, and probably all newer Euro 4 models.

Ah, I've learned something new! I thought the valve was just a simple shut-off valve. So, the valve is also used as a throttle valve for EGR regulation.
Now I understand the software change that was made to my AXR, which was causing the jerking and vibrating.

Based on the information from Gremlins, it seems like the options are mutually exclusive; it's either one or the other, but not both (DK or AK).
Let me take another look... I don't see any ambiguity, at least.
Read cheerfully.
OlBe.

From my technical understanding, a DK can also be an AK (or at least it can be).

An AK can only be OPEN or CLOSED, while a DK can be anything in between!

m;

olbetec wrote:

From the Gremlins documentation, I only understand an either/or, but not both (DK, AK)... Let me take another look... I don't see any ambiguity, at least. Read cheerfully. OlBe

Dear OlBe,
You didn't read my post correctly!
I thought it was an AK, but Gremlin claims it's a DK. What's ambiguous about that?

Wenn die DK beim Abstellen geschlossen wird, wirkt sie ebenfalls wie eine AK. Genau das war meine Aussage. Nothing else!
The flap in the picture above closes when I park my AXR, and I can be certain of that.


EDIT:

dieselmartin wrote:

From my technical understanding, a DK can also be an AK (or at least it can be). An AK can only be OPEN or CLOSED, while a DK can be anything in between!

I see it exactly the same way.