VW Touran shuts off immediately after starting (Weblog mannimaus)

Translated on 03-07-2026, 15:19.

Hello, I'm desperate.
The engine starts for about two seconds when cold, then immediately shuts off. It doesn't maintain an idle speed. When the engine is warm, everything is fine. If I increase the RPM to around 2000 for about 2 minutes, it then works perfectly.
Diesel tank pump, checked: delivery pressure between 0.5-0.8 bar.
Replaced the relay for the diesel fuel pump.
Checked pipelines for air pockets.
Oil pressure sensor replaced.
Coolant temperature sensor replaced.
The engine doesn't smoke, but it starts immediately and then dies.
VW Touran 1.9 TDI, year 2009, chassis code 1T BLSAG.
I would appreciate a response.

Translated on 03-07-2026, 15:19.

Hello,

Welcome! It sounds like there's air in the fuel injection system, so I would check if the injectors and their seals are okay, and make sure all the fuel lines are tight.

Best regards, Rainer.

Translated on 03-07-2026, 15:19.

Hello Rainer, thank you for the reply. I've already tested it with a transparent hose, but no air is entering. It also starts immediately and doesn't smoke. If the PD (presumably referring to a fuel pump or similar component) were leaking, it would also smoke because fuel would be entering the cylinder. It also starts immediately, and when I... (the sentence is incomplete).
"When I increase the RPM to 1500, it immediately continues running, but it only stops when I reach the idle range. This happens for about 2 minutes. Then, when it's warm, it seems like the oxygen sensor isn't preheating, or it might be coming from the auxiliary heater, because VW updated that software with a "trick." Since then, the car has also been smelling bad."

Translated on 03-07-2026, 15:19.

Autoscan?