Kaltstartproplem beim 1Z nicht gelöst *heul* | Posts 192+

I've now run my RAID array again .

Okay, here's what happens during startup: The fuel quantity control unit is set to the initial fuel quantity. As the engine speed increases, the feed pump builds up pressure in the pump housing (and it needs at least 150 RPM for this, meaning the starter motor needs 300 RPM!). Only when this pressure is high enough can the injection timing advance. The injection start timing is NOT controlled at this stage; it's not possible yet because reliable signals from the needle lift sensor are not available. Instead, it's controlled based on a lookup table (map). Initially, the valve for injection start is closed, and the injection start advances to its maximum early position as the pressure increases. Once the engine starts and usable signals from the needle lift sensor are available, the injection start timing is regulated.

If the device ('the box') doesn't start up when it's around 0 degrees, here are some scenarios that I can think of:

- The valve for the start of injection is stuck.
- The pressure valves for the injection line are worn out.
- The booster pump is worn out.
- The pressure regulating valve is worn out.
- starter speed too low.
- Defective temperature sensor (water or fuel).

Please remember, there are the most incredible coincidences (you know them all).
It wouldn't be the first component to fail only within a specific temperature range.

Sure, here is the translation of the text from German to English:

'Cu Gremlin'

Deleted upon request.

He's right where he's right. I can barely get my own (rather sporadic) posts out of my head, let alone keep track of them in sequence.
I think it would be best if Christian started a new thread with a summary of the old one.
So, the problem is: what exactly was done, what was proposed before, and why didn't it work?
Perhaps a more detailed analysis will reveal several different themes. Unfortunately, I lack the overview and am too lazy to read everything again.

diesel.gustav wrote:

...Ich bin kein Stammgast hier und kann auch auf Wunsch jederzeit wieder verschwinden...

Hi Gustav,

... that you absolutely don't run away from us .

Hi diesel.gustav,

I completely agree with Bertil: stay here!

Otherwise, I think that this forum is characterized by an enormous willingness to help (shared sorrow is half a sorrow ).
Haehnle's thread here provides a compelling example of this.

@Christian Haehnlein:
Start a new topic and let's organize this mess first.

Markus H. wrote:

Ansonsten finde ich, daß sich dieses Forum ja eben durch eine enorme Hilfsbereitschaft (geteiltes Leid ist halbes Leid ) auszeichnet.

You are absolutely fantastic!!!!!!!! Thanks to your help, I have gone from being a practical mechanic to a TDI theorist (well, somewhat ), and hopefully other readers as well .

Best regards, Christian .

Hello everyone!

Although this thread is already quite full and my last post was a while ago, I wanted to briefly share my experience with you.

The problem was: difficulty starting the engine when it's cold, plus white smoke!

Troubleshooting: The injection timing was at 17°, which is far too early. After adjusting the pump using a multimeter on the fuel injector adjuster (2nd gear, full acceleration, 0.9-1.3 volts) and increasing the starting quantity, there are no more problems; it starts with one glow cycle. However, white smoke is still present during startup, although much less so and only for about 2 seconds. The engine also runs much smoother, but it doesn't pull quite as well in the higher RPM range.

The setup instructions using a multimeter are excellent and relatively quick to complete. Thanks to the authors!

Best regards,
Wolfgang.


'1994 Passat Variant with a 1Z engine.'

Here is the end .
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
That's where it continues .