1Z Engine Starting Problems - Workshop Stumped?

Hello to those who know.
I've been driving a Golf 3 TDI with 66 kW since December 2000. In the same month, the car broke down. When I restarted it, the engine revved to 3000 rpm and immediately stalled. It also smoked heavily. The fuel injection pressure sensor (G149) showed a regulation difference and upper/lower limit values. The ESP (electronic stability program) was replaced under the used car warranty. It worked well for 6 months. Then, the same problem occurred again, and this time, the ESP and the engine control unit (Mot-SG) were replaced. It lasted for 4 weeks. The same behavior persisted. The workshop then checked the wiring harness, but without success, because the car suddenly started working again. The VW dealership said, 'The car should be returned to the customer.' However, I'm not satisfied with this solution, because the warranty only extends until August.
Who can help me?

Hi, I think the workshop is unwilling to provide a replacement pump. It sounds like another RME issue (rotor damaged - debris in the metering unit, etc. / see 'performance problems 2.5l Audi' - other posts).
Sure, here is the translation of the text from German to English:

'Gr.W.' translates to 'Great Britain' in English.

Hi.

Somewhere in the error database, I believe there's information about similar symptoms when the engine control unit identifies the idle air control valve as faulty.

Just for the sake of completeness - if I were to choose, I would probably lean towards W.

Of course, there's also the possibility of a loose connection in the pump cable harness, which can be "deceptively" hidden when testing (since disconnecting the connectors can shift the cables and change their position).

To detect such "temporary" cable breaks, I run approximately 3 times the ampere rating for the respective cross-section through the cable, and I move the cable piece by piece: then, the power loss at the break point leads to significant heat generation and, possibly, scorching marks on the insulation - but that's exactly where the cable is already broken --> repair it and that's it .

@W: How many cases of pump failures due to biofuel operation are you actually aware of, or, based on your experience, what is the approximate failure rate in such cases (1 defect per ??? vehicles operating on biofuel)?

Hello Wilhelm, hello Ulf.

Imagine that I found the bug this afternoon.
I myself (although the workshop claimed they had already done it!?) followed Ulf's suggestion and examined the entire wiring harness.
As soon as you unplug it and measure the contacts from the motor control unit, everything is fine, but: The cable in the power supply line to the ESP has been chafing against the water pipe on the right side of the motor. With a little skill, the workshop should have found that; oh well.
I checked the wiring diagram and found that this cable connects to pin 6 of the connector leading to the ESP (Electronic Stability Program). This pin connects to the quantity control valve G146, which explains the errors.

Hopefully, that was it.
Great!
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hi

...on the topic of "reflection among workshop staff."

If even laypersons almost regularly find solutions to problems that workshops struggle with (if they even "botherto" at all???), then that confirms the prevailing prejudices of incompetence, indifference, sloppiness, and accounting as the only reliable quality.

Unfortunately, people tend to talk (or post) more about negative experiences than about positive ones, which likely distorts the perception of the actual quality of the VAG workshops.


@Cashmi:

Was the abrasion mark reasonably visible?

If the cable is not only frayed, but also has several broken wires, I would recommend soldering in a new piece to prevent the conductor from completely breaking, especially when you might be overtaking a vehicle on the highway --> which could cause the engine to suddenly stall.
Then, your potentially fatal accident would only add one mark to the statistic of "illegal overtaking" .

Hi, it's interesting that RME is affecting the seals; do you see any connection?
Hi Mucki,