Identify Donors: Find and Contact Them | Posts 32+

Bertil wrote:

I can tell you that from memory: ~5 Ohms

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Hi Bertil.

That is then the (common) inductive sensor.

It's possible that your signal box's mechanism is a bit stiff, which could then cause slight oscillations.

Have you ever removed the pump cover and manually moved the valve mechanism to see if anything is rubbing or causing friction?
Approximately, the measuring ring is located on the round magnetic plates... ?

Hi Ulf,

I haven't dared to do that yet. I think it's probably due to the stiff signaling system.
What should I be aware of when removing the cover (I think you mean just the top cover)? The Bosch service technicians removed both covers back then, including the flow meter.

Just to reiterate: My car doesn't shake when coasting, but rather up to approximately 2000 RPM under light load. When I give it full throttle, the problem disappears. Even when driving steadily (with cruise control) at 50 km/h on a flat surface, it still shakes.

Hi Bertil.

Quote:

What should I be aware of when I remove the cover (I think just the top one)?

The Bosch service removed both covers back then (including the flow meter). }

Get the right tool for that badly damaged hex screw, or make one. First, loosen all the screws only about a quarter of a turn (so that the cover doesn't bend due to the pressure of the sealing ring). Tighten them in the reverse order.

If you want to avoid diesel fuel spillage, before removing the cap:

1. Disconnect the fuel line leading to the pump at the nozzle and use a large syringe to blow air through it until you hear bubbling in the tank.

2. Disconnect the return hose from the filter and seal it on the pump side.

3. Disconnect the pre-filter and place it in a collection container.

4. Using the syringe, apply pressure again to the leaking line. This will force the fluid (very slowly) out of the supply line.

5. When approximately 50 ml of liquid have been collected in the collection container, reattach the hoses. Then, the pump cover can be removed without any spills.

I'm going to start a new thread shortly about another "bump theory." It will also include further information about the RWG check.

Hello Dieserschrauber,

Okay, I'm already having problems understanding the term 'fuel mixture adjustment' when it comes to diesel engines.

Normally, a diesel engine always operates with an excess of air; otherwise, we would see a lot of smoke. Additionally, increasing the fuel injection amount will increase the engine's power output, or its RPM.

From this context, it follows that for a given engine speed and power output, a specific amount of fuel is required. This corresponds to a particular setting of the fuel quantity control system, which is reported as a value in mg/hub using a VAG-COM diagnostic tool. Since the fuel quantity control systems are not finely tuned with the engine control units, a relatively large tolerance in the fuel quantity reading should be expected, especially at low fuel injection rates.

Unfortunately, VAG-COM doesn't provide enough detail to determine exactly what the fuel injector assembly is doing when it's malfunctioning, because the time interval between measurements is too long. In my 1Z, I discovered a faulty fuel injector assembly because the values for the fuel injection quantity at idle were fluctuating between 0.8 and 6.0 mg/stroke, and at 1600-1950 rpm, they were also not constant.

Klaus.

Dieselklaus wrote:

Unfortunately, using VAG-COM, one cannot actually determine what the suspension control module is doing in the event of jolting, because the time interval between measurements is far too long.

It's especially nice to revive an old thread (over 2 years old!) and then not have anything new to say.
In some of the more recent posts about "pump-and-dump" schemes, we have already made and clarified the observations you have made.
Also bitte demnächst erst lesen dann posten ... Thank you .


By the way, this thread is so old that I haven't owned the car (the 1Z) I described for two years now!

Hello everyone!

After having read all the reports in this forum about the jerking/stuttering issue at low load, I still want to ask a question because I am also experiencing this annoying problem.

Here are the details.
Volkswagen Golf 3, 66kW TDI engine, 340,000 km.

Measurement block 1, measured with VAG-COM.

Idle speed.

fluctuates between 883 and 903 RPM.

Injection amount.

fluctuates between 3.6 mg/H and 4 mg/H.

Voltage sensor, control slide position.

1.44 V

Coolant.

76.2°C

After disconnecting the speed signal from the transmission, it now runs smoothly without jerking, but of course with increased fuel consumption.

What do you think, is it only a pump replacement that will fix the issue, or are there any other potential causes I should check before replacing the ESP?

Thank you in advance.

Best, Frank.