Starting problems in warmer temperatures + solution!!

Hello!
I'm having the following problem with my A6; 2.5 TDI (year of manufacture: 1994 - model: 1995).
Every morning, when I start the car for the first time, it's difficult to get it started. It only glows for a short time, if at all. Once it's started, everything is fine.
If he pre-glows properly, like in winter, he doesn't have any problems starting.
When I unplug the coolant temperature sensor (2-pin connector), it stays lit for a long time (until the engine starts), but it starts up perfectly fine!
What I have already done:
Replaced the glow plug relay located under the dashboard (socket 6).
Spark plugs checked, all 5 are OK.
Coolant temperature sensor replaced.
Temperature sensor reading: at room temperature: approximately 2 kOhms; in the vehicle, approximately 2 hours after operation: 580 Ohms.
Replaced the fuel filter check valve.

I also tried something else: I took some resistors and used them instead of the temperature sensor. The glow plugs activate at 7k ohms!

Can someone help me?

Thank you.


Solution:
Apparently, the fuel injectors are the problem. In my model, there are 4 of them, and don't forget the needle lift injector, which also functions as an injection nozzle!!

If this solves my problem, I will report back here. Unfortunately, I won't receive the parts until Monday!

I'm experiencing the same problem with the 1Z.
I've already replaced the fuel injectors, but it didn't make any difference for me!

Hello,

You can also try to increase the initial amount.
However, a diagnostic tool is required for that.

You can find information on how the procedure works in the archive.

Hello,

If it starts with preheating and doesn't have any other issues, then perhaps the cheapest solution would be to simply insert a switch into the circuit leading to the temperature sensor (which controls the preheating time). The switch could be placed on the dashboard. The Mercedes solution would involve a time relay that is activated when the ignition is turned on. Perhaps it would be possible to connect a resistor in series with the temperature sensor to increase the temperature threshold of the glow plug system.
All of this will certainly affect the lifespan of the glow plugs. If I'm correctly informed, a set of new injectors costs over 800 euros. The candles are likely priced from 10 euros per piece.

Regards,

Eike.

Hello,

You can also try to increase the initial amount.
However, a diagnostic tool is required for that.

You can find information on how the procedure works in the archive.

Unfortunately, I can't find it, Michael. Can you repost it, or tell me why I always get a 'not found' message when I try to access the old archive?

Best regards, Lanz.

Hello,

with a diagnostic tool (e.g., 1551, 1552, VAS, or VAG-Com...).
to access the engine control unit.
Perform a login using the code 12233.
Select "Function Adaptation".
In channel 5 (initial value), the value can now be increased.
This results in a slightly increased initial amount.