AFN Won't Start? Troubleshooting & Help!

Hi,

I think I posted about this topic some time ago, but I still haven't found the error. Maybe someone else will have an idea about it.

'I had a timing belt failure on my TDI AFN (with a chip). The valves and hydraulic lifters were completely damaged. I had the cylinder head rebuilt and reassembled the engine. There were no marks on the pistons, so the engine block is okay.'
Then it wouldn't start anymore. I took it to VW for two weeks, and they couldn't find the problem (cost: €700). I replaced the fuel pump, injectors, and control unit, but there was no change.
Then I pulled it to start with a rope, and it started right up. However, it only runs when stationary; it doesn't respond properly to the throttle, it runs very unevenly, and it's producing a lot of white smoke.
I've adjusted the timing several dozen times and checked everything. It's probably just a small detail that I can't find.
I also had the compression checked. It was initially very low (16 bar), but after several attempts, it finally reached the correct level (30 bar).

Any ideas? If all else fails, I might have to buy a new engine. Does anyone know of a supplier in the Munich area?

Thank you and best regards.
Sneezy.

Hello,

Check if you're losing coolant; that might explain the white smoke.

Has the head been inspected for cracks?

Is the ZKD (thermostatic clutch) installed correctly, and have the specified torque values etc. been adhered to?

Regards,

Faxes.

He doesn't lose any coolant, the cylinder head has been completely reworked and inspected, the head gasket is properly installed, always using new gaskets and new bolts, and the correct torque was applied.

Regards,
Sneezy.

Incorrect injection timing.

Best regards, Rainer.

'I also had a belt failure on my AFN engine, and I didn't see any damage on the pistons. It was difficult to start, and it required a lot of oil all at once.'
You might want to consider spending another 360€, take the head off, remove the pistons, and just replace the rings. That's what I did, and everything was fine again. In my case, the oil scraper rings were broken, but the piston rings were still okay. The fact that it's smoking white is a bit strange.
Hopefully, I was able to help you.

Hi there,

I experienced the same thing. The belt broke at approximately 4000 RPM.
3 valves were replaced, but there are no signs of leaks. After the head repair and adjustment of the injection timing (static and dynamic), it smoked white for about half an hour. It hasn't smoked since.
Could it possibly be air in the fuel system?
I have now driven over 40,000 km, and I haven't experienced any problems. The oil consumption is approximately 1 liter per 10,000 km.
By the way, the engine (AFN) is actually in a T3 Syncro 16" camper van, so it has to work a bit harder to move the 2.2 - 2.6 tons.

greetings
dieter

[Translating...]was heißt statisch und dynamisch?

schnupfi wrote:

What does "static" and "dynamic" mean?

Hi,

static: with a dial indicator -> it's no longer useful for the TDI (at least not for mine)

dynamic: using VAG-Com with the engine running -> this is the recommended procedure.

Before you go completely crazy (see my mega-mega article "White Smoke" ), just try adjusting the timing a bit: loosen three screws from the bracket and the fourth one below the fuel injector connections, and rotate the pump until it hits the stop in the direction opposite to the belt's rotation (it will probably say "too early" -> but that doesn't matter for this test).

Simply put: It's dynamically controlled via the software and statically controlled via the ESP (fuel injection pump) housing.

Best regards, WarLord.