Beetle TDI ALH won't start

Hello

TDI ALH
Filter updated
Get the fuel pump checked.
Check the fuel injectors

Everything is great.
Lines filled with diesel and bled.
OT Funding Start Suspended
KW Sensor replaced

Who has more ideas?

LG

Hello,

Likely, air has entered the fuel injection pump and further into the fuel injection lines.

With air in the fuel lines, the starting process becomes difficult because the air is highly compressible. Before the nozzle opens, the fuel pump's injection process is already complete, and the air does not come out of the line.

It is sufficient to loosen the retaining nut on a nozzle holder combination; a helper then activates the starter for as long as it takes (less than 10 seconds) until diesel sprays out of the connection. A rag can help. Then reassemble and start, and the remaining cylinders will also come.

To illustrate:
Replacement of fuel injectors/injector holders on a VP-TDI, "Overrunning nut fuel line" in the image.

Of course, the diesel filter must be filled with diesel before assembly, and the hoses must be properly connected, i.e. the forward/return lines must not be mixed up, etc.

Best regards, Rainer

Is there a backstory?

Hello Rudy
The timing belt was replaced 3000 km ago.
Fuel injectors and pump were inspected and cleaned.
Various vacuum hoses and glow plugs have been replaced, as well as the coolant temperature sensor, battery, and starter.
Fuel cap, indicator relay, and relay 109 replaced.

To get started, the following was absolutely pointless:
- Replace vacuum hoses (However, using "gammelig" (leaky) oil lines makes sense)
- Starter without checking the starting speed with VCDS
- Battery without checking the starting RPM with VCDS
- Glow plugs/pre-heat relays, except when temperatures are below freezing
- Fuel cap
- Coolant temperature sensor (If you have VCDS, you can check the value and decide if it is plausible. But, frankly, it doesn't really matter, as the ECU continuously increases the starting amount until the engine runs)
- Relays 109 are useless if you have VCDS. Does the diagnosis for the ECU also show that it is receiving power?
- Checking and cleaning fuel injectors is also often pointless, as a poor spray pattern or incorrect opening pressure will not prevent the engine from starting. One can't really verschandeln it up anyway.

I have noticed that almost all the actions taken were essentially pointless, and must have cost a fortune. Furthermore, there was no reasonable explanation for the error, nor any feedback on my suggestion, which was based on the assumption that the problem occurred after a diesel filter replacement.

Porous drainage pipes have been replaced.
Starter only works up to 130 u/min according to VCDS

Coolant temperature sensor showed 28 degrees at 10 degrees, so replaced.
Fuel injectors and pump were simply cleaned and inspected at 286,000 km.

But it must have all been nonsense, surely.

If I say something that is nonsensical, then you must believe it. Because you probably don't know anyway, otherwise the car would already be repaired.

Does the car start now, or is it not starting? Does he not start at all, or only after a long period of organ playing...? There's so little information, what can one say about it?

It can't be that I have to guess in order for you to provide meaningful information.

The car is in the garage, because it's not my old Volkswagen.

Earlier, only diesel fuel from cylinders 1 and 4 was being supplied.

With 130 revolutions, the engine control unit does not issue any approval for starting the engine.

Exactly for this reason, the starter was also replaced.

And what did that result in in terms of RPM?

Hi Rudi
According to VCDS, the new starter motor requires 318-320 revolutions per minute.

My AFN (presumably an automotive part) makes over 500 revolutions when the starter motor is engaged.

Can I re-program the engine control unit to work with an automatic transmission?