Passat Starting Problems: No Error Code, Help!

Hello fellow enthusiasts,
My old 1995 Passat with a 1Z engine has a starting problem. In the morning, it takes about 4-5 seconds to start, and when it's warm, it still cranks for 2-3 seconds before starting. This is not normal. A year ago, all you had to do was touch the key and it would start right up.
According to the Hoppel test, the compression is fine (when climbing a 10% incline in 2nd gear, it 'hoppels' every 8 seconds). The fuel supply also seems to be okay, with no large air bubbles.
Once it starts, it runs normally.
I once let it idle and read the diagnostic groups using VAG-Com. In my opinion, there aren't really any noticeable issues except perhaps with group 13, the idle speed smoothing. The values are all quite different. Please take a look at them and give me your expert opinion: Here are the values at idle.
Group 1: 903 RPM; 4.4 mg/R; 1.5 V; 65 °C.
Group 2: 903 RPM; 0.0%; 010; 65°C.
Group 3: 903 RPM; 259 mG/R; 259.4 mg/R; 53%.
Group 4: 903 RPM; 0.4° BTDC; 1.5° BTDC; 5.5°.
Group 5: 882 RPM; 22.4 mG/R; 1.5 degrees BTDC; 71°C (slowly warming up).
Group 8: 903 RPM; 1.2 mG/R; 28.2 mG/R, 21 mG/R.
Group 9: 903 RPM; 0.0 mG/R; 51.0 mG/R; 1.940 V.
Group 10: 442 mG/R; 991.2 mBar; 1016 mBar; 0.0%.
Group 11: 903 RPM; 940 mBar; 1016 mBar; 93.4%.
Group 13: -2.3 mG/R; 1.57 mG/R; -2.97 mG/R; no value displayed.
Group 15: 903 RPM; 4.6 mG/R; 0.37 l/h; 1.2 mG/R.

The experienced people among you can surely tell me if something is very unusual. Please take a look at this.
If nothing else works, I'll take out the fuel injectors tomorrow and check the spray pattern, but I hope one of you can give me a tip about what it might be. Best regards, Harri.

95 octane, 1 cylinder?

It's possible that it still has the "soft" crankshaft bolt.

Okay, let's find out what her name is.

And search for the crankshaft bolt and read everything .

m;

Okay, I went outside and checked. Folks, it's going to be a cold night.
'The screw is marked 'Kamax 12.9' and it's a multi-spline screw, it looks quite old. Was this type of screw affected? If so, can I still drive the car, or will the timing belt continue to slip --> leading to a complete failure?'
Best regards, Sven.

Okay, the 12.9-grade bolt is already the "standard" one.

If the screw and gear are securely fastened, there should be no immediate risk to life.

If the stuff is loose, then yes.

What do the usual suspects say (e.g., injection timing, air in the diesel system, diesel filter, etc.)?

m;

There's no air in the line, but occasionally a bubble appears (about every 10 seconds when idling). I already replaced the filter a week ago because there was more air, and I was also experiencing the problem of it not starting.
Regarding the 'Spritzbegin' function (if that's what the TDI timing checker is), I can't say anything yet because I only have the shareware version of VCDS. The full version has already been ordered and paid for (please send the CD soon, it's urgent).
Today, I'm going to remove the injectors and lines and rotate the entire assembly 90 degrees at the diesel pump. This will cause the injectors to spray into nothing, but I can see if they are atomizing properly.
That's really messed up.
Best regards, Harri.

Harri wrote:

... because I only have the shareware version of Vag-Com. The full version has already been ordered and paid for (please send the CD soon, it's urgent)...

Hi Harry,

What is your order number, or what is the customer name?
I can't find anyone named Harald or Harri within the current order period.

Best regards, Rainer.

Hello Rainer,
I'm logged in using my middle name. The order number is 476, and you shipped it today (according to the email). I'll probably receive the CD on Monday.
Best regards, Harri.

Hello,

You're right, it was released about an hour ago. Unfortunately, it often takes quite a while for our bank to update the account statements. :-/

Best regards, Rainer.

Okay, here's the data from the start of injection:
3° ATDC before starting.
1.4° BTDC after starting.
and the more I advance the timing, up to 10 degrees BTDC.
What does ATDC or BTDC mean?

'I also noticed something today when I removed one of the injectors and tested it in the air. A lot of diesel was leaking out of the return lines during the starting process (it was significantly less on my older 1.6-liter VW diesels). I couldn't see any abnormalities in the spray pattern of the injector itself. However, it always took a while for the diesel to start flowing initially. Nevertheless, I would like to test this properly again. Does anyone here (in the Rhein-Main, Rhein-Neckar, or Unterfranken area) have a diesel injector testing stand?'
'Two glow plugs have infinite resistance, so I need to replace them. But won't they still heat up if the temperature is above 5°C?'
Greetings, Harri.

Hi,

ATDC = according to O.T.
BTDC = Before Top Dead Center.

Yes, the glow plugs are not used when the temperature is above 5°C.

Best regards, Rainer.

Hello, today I noticed that the car is shaking slightly while driving. It might be time for a new fuel injection pump. } I need one for a 1Z with Bosch part number 0460 404 994. } Does anyone know where I can find this part at a reasonable price or have it repaired?
Best regards, Harri.