Cheap 1Z Fix: Quick & Easy Solution

Hello! I'm also a new owner of a Passat TDI 1Z. The car was first registered in 02/1994, has 216,000 km on the odometer, and features the electronic speedometer.

I'm experiencing the typical 'load-dependent shuddering' on my vehicle, meaning it shudders at partial loads of 1500-2200 RPM, especially in 4th and 5th gear.

'So, I also immediately disconnected the speed limiter from the transmission --> the jerking was gone! My friend also has a Passat 1Z, but with a speedometer cable. He simply disconnected the connector from the instrument cluster, and that was it (meaning the speed is displayed normally). He's just foregoing the comfort features, and I couldn't notice any difference while driving.'

I also want to do this now, but I don't have the connector at the instrument cluster. Therefore, I'm looking for a way to remove the speed signal from the ECU, or does the signal first go to the ECU and then to the instrument cluster??

Can anyone help me here? daaaaaanke

My alternative attempts would be:

- DIY anti-ciliate treatment.
- diesel filter (unlikely)
- LMM (unlikely)
- new MSW (bosch says that it will cost me 800 EUR including installation ).


What do you think about it? Thank you for all the contributions.

chimps wrote:

I want to do the same thing now, however, I don't have the connector at the instrument cluster because of that, I'm looking for a way to remove the speed signal from the ECU, or does the signal first go to the ECU and then to the instrument cluster??

If you had done a little more research on the subject, you would have realized that your speedometer is powered by the engine control unit (ECU). Therefore, if the ECU stops receiving a speed signal, your speedometer will no longer work.


Why are there still people who believe that it's possible to circumvent this clear-cut error?
Having discussed this topic countless times (especially in recent weeks), and knowing that the only sensible solution is to replace the pump, any further explanation seems unnecessary.
Furthermore, there are already people here (DocSnydor) who have replaced the pump on the 1Z engine and were then free from the misfiring issue. Everything else is just a shoddy fix!

Why not just replace the fuel flow meter? It probably won't cost as much as a new pump. Sure, it might be a hassle to get the pump properly adjusted, but it's probably cheaper than replacing the entire pump. I'd check with Bosch to see how much a fuel flow meter costs and try it myself.

mersente wrote:

Why not just replace the fuel flow meter? It probably doesn't cost as much as a new pump, although it will be a hassle to get the pump properly adjusted, but it's definitely cheaper than a replacement pump. I would check with Bosch to see how much a fuel flow meter costs and try it myself.

You are absolutely right.
A cheaper option is to replace the fuel pump itself, but not every Bosch service center (let alone a "friendly" one) is capable of recalibrating the pump on a test bench after the replacement.

Furthermore, when repairing the pump for the workshop, there's the issue of the warranty. Many people try to circumvent this legally by replacing the entire pump.

With my previous 1Z, I had a warranty for both scenarios (pump replacement and MST repair). The difference was about 200 euros. With the pump, I would have had full warranty, while with the repair, it would only cover the quantity setting device. I guarantee that the pump would have broken down shortly after.

I don't think I would blame anyone if they replaced the entire pump.

Those who have the opportunity to choose are naturally in a better position.

If you had done a little more research on the subject, you would have realized that your speedometer (tachometer) is supplied with data from the engine control unit (ECU). Therefore, if the ECU no longer receives a speed signal, you will also no longer have a speedometer display.


'That's not true, at least for Audi B4 models with the 1Z engine and with an electronic speedometer. The speed signal actually comes from the engine to the speedometer, then goes back out, and ONLY THEN goes to the control unit. In other words, you cut the right wire with wire cutters, snip it carefully, and the jerking will stop. This repair costs exactly 2 euros if you don't already have wire cutters. At Praktiker, everything is currently 20% off, so the repair only costs 1.60 euros! ((-:'

Übrigens, da das Auto bei der Abgasuntersuchung auch steht und nicht fährt sollte diese Massnahme auch keine negativen Folgen haben. Wers ganz schick macht baut einen kleinen Minischalter ein und schaltet den nun offenen Eingang vom Steuergerät mit einem 10k-Widerstand gegen Masse. MI don't know.

Best regards,

Ralf.

Hi Ralf,

Unfortunately, this method has its drawbacks.
a) GRA is no longer available.
b) Rear shock absorption is dead (possibly, the car might rock back and forth in the lower gears or bounce at the traffic light like a mountain goat ).


It's definitely worth a try, and it's certainly cheaper than replacing the fuel injection pump.

Best regards, Rainer.

@Rainer:

Hello.

'Of course, removing an input from the control unit will definitely have consequences. However, I have to say that before I came up with the idea and mentally forced myself to cut the cable, I probably drove around for about 2 years. This caused the ribbed belt to break several times, and I always got incredibly angry when I had to drive longer distances, as the shaking made me completely exhausted. Objectively, the power delivery isn't quite as smooth when accelerating, but compared to before, my car now feels like it's floating on cloud nine. Honestly, the shaking was so awful that I almost wanted to file an insurance claim for the car. VAG was completely unhelpful and only wanted to replace parts. I absolutely cannot observe effects like swaying or bouncing when starting. And I've now driven over 10,000 kilometers with the disconnected input.'

Best regards,
Ralf

Rainer K. wrote:

Unfortunately, this method has its drawbacks. a) GRA is no longer available. b) Rear shock absorption is dead (possibly, the car might rock back and forth in the lower gears or bounce at the traffic light like a mountain goat ).

And the automatic shut-off function is no longer working... -> Increased consumption.

It's interesting that the wiring is different in the Audi... I wasn't aware of that.

Quote:

It's definitely worth a try, and it's cheaper than replacing the fuel injection pump.

Nevertheless, it remains a makeshift solution that only addresses the effects, not the root cause. Such "repairs" are simply shoddy work.

@Bertil
Are you sure about the implications?
Okay, I've been dealing with error code 625, "implausible speed signal, intermittent," for about six months now. I suspect that the control unit sometimes doesn't receive a speed signal, but I haven't noticed any difference. The turbocharger kicks in normally, there's no hesitation or jerking when starting from a stoplight, and there's no increased fuel consumption.
On the other hand, I once had the clutch and one of the brake switches disconnected, which resulted in the described jerking when starting.

/Jan

Jan03 wrote:

@Bertil Are you sure about the implications?

Sure, I drove my 1Z for a test without the speed signal, and it was more like "riding" than driving. Every time I gave it gas from the boost mode, the car would jump. When starting, the drive shafts would creak because the torque limitation system can't regulate properly. I'd rather not think about how long the drivetrain will last under those conditions.
The jolting during the ride was definitely gone, but the side effects were unacceptable.

It's possible that some control units might not reveal such errors as prominently.

Hello, fellow Ruckel enthusiasts!

Nachdem das typische Mengenstellwerkruckeln mich genug genervt hat,habe ich meine drei Schlüssel zusammengesucht und die Einspritzpumpe geöffnet. Nach Aussage des Boschdienstes müsste ich eigentlich Ablagerungen in Form von Rost bis Metallspänen mit einem Spachtel abtragen können. Aber - nothing -
I then blew everything out with compressed air and put it back together.
After a slight adjustment of the carburetor on the pump, the engine started, but it didn't respond well to acceleration. I then, with the engine running and the screws slightly loosened, used a plastic hammer to find the optimal setting, which I found relatively easily. If the carburetor is shifted too far towards the clutch, the engine does become more responsive, but the RPM drops slowly.
But, as I said, it's easy to achieve with a little empathy.
If this success proves to be lasting, one would actually have to accuse the experts in the field of fraud.

Best regards, Benno.

Benno wrote:

If this success proves to be lasting, one would actually have to accuse the experts in the field of fraud.

If your workshop did that, they should provide a warranty for it.
Would you offer a 1-year warranty on your cleaning service?
Well, not me, it's too risky for me. Nowadays, workshops are forced by strict "consumer protection laws" to only replace entire parts. A repair could mean bankruptcy for the workshop if there's a claim for damages.

There might have been parts in your pump that you didn't (immediately) see. Even those can throw a V-belt off. In that case, the chances of your action being successful are quite good.

This action is the only correct one... Check what the quantity setting device shows.

Hello Bertil.
Regarding the warranty, I see things a bit differently. The workshop only needs to provide a warranty for their work. In this case, that would be the cleaning and reassembly of the pump.
She cannot be held liable for the longevity of the cleaning because she is not responsible for the cleanliness of the fuel. Furthermore, a work order can clearly state that recontamination can occur at any time. I believe that the workshops are not interested in a repair that is beneficial to the customer because they can make more money otherwise.

Best regards, Benno.

Hi Benno,

Benno wrote:

..... The workshop only needs to guarantee its work. In this case, that would be cleaning and reassembling the pump.

Okay, but if something went wrong during the assembly process and it only becomes apparent later, the workshop will also have problems with liability. Legally, it even means that the workshop has to prove whether or not it was the case. In the past, the customer had to provide the proof. An expert opinion can quickly cost an extremely large amount of money.

Quote:

She cannot be held liable for the longevity of the cleaning because she is not responsible for the cleanliness of the fuel.

Auch diesen teuren Nachweis muss die Werkstatt führen! Not the customer!

Quote:

Furthermore, a work order can clearly state that recontamination can occur at any time.

While that can be ruled out, unfortunately, it is not applicable.

Quote:

I think it's more likely that the workshops aren't interested in providing customers with cost-effective repairs, because they can make more money otherwise.

Based on my experience as a workshop manager in an industrial maintenance company, I can tell you that it's not always the case.

A small example:
The cassette player's head is dirty. I'm cleaning it. Two weeks later, it's dirty again. The reason for this is a worn-out head. The surface roughness of the head grinds the tape, which clogs the mechanism.
If you were to only replace the read/write head now, the entire abrasive residue would still be inside the drive. Cleaning is possible, but it would be extremely expensive.
The drive costs 25€, while the cartridge "only" costs 8€ + 12€ for installation and adjustment, totaling 20€, which is a difference of 5€ (for which I can't clean the drive).
So, I'm just replacing the head (because it's cheaper). After 4 months, the device comes back with a faulty coupling that slips due to wear (we assume an expert has determined this). So, I, as the workshop, now have to install a new drive for free. I can only charge the customer the €5 difference for the drive. I have to bear the costs for the expert, the double amount of material used, and the double amount of labor. In addition, I'm dealing with a frustrated customer who is also upset about a messy repair.
So, I would replace the entire drive right away. The customer benefits significantly, and I have the assurance of a clean repair.

Here's how the situation looks from the workshop's perspective: It's better to help the customer with minimal additional costs.
Often, cheap isn't always the best option.

hi!
Okay, so I went to a workshop that specializes in diesel injection pumps, and they also have testing equipment and expertise! It's not some small, fly-by-night operation.
I was told that the lid of the MSW (presumably a container or device) could be opened without any guilt or fear.
To eliminate or reduce the jerking, you should gently press the contact point slightly *away* from the indicator that is always moving. This adjustment should be very small, so don't push too hard! This will allow the engine to receive a bit more diesel and run better or flawlessly again.
You should listen to someone like that; a man with experience from a diesel pump testing workshop in Düsseldorf knows what he's talking about!

Unfortunately, I haven't been able to test it yet because the special screw with the special head cannot be loosened with a size 7 socket. You really need the tool, which no Bosch dealer in my area wants to provide...

Okay, if someone tells me how to remove the screw without welding anything to it, hammering it, or otherwise destroying it, I'm willing to be the guinea pig and try it!
Does anyone have any ideas?


I'M NOT MAKING ANY GUARANTEES THAT THIS WILL WORK, AND I DON'T WANT YOU TO DAMAGE YOUR CAR. BUT IF I CAN GET THE COVER OFF, I'M GOING TO DO IT!
SO, I AM NOT RESPONSIBLE FOR ANYTHING!!

subman82 wrote:

To eliminate or reduce the jerking, you should slightly push the adjustment plate away from the indicator that is always moving.

This is only a very small adjustment. https://community.dieselschrauber.org/en/viewtopic.php?t=3066
Hm, before that, you could show us something based on the photo in this link }.
describe more precisely where exactly you need to press and in which direction.
(PRESSING is not such a precise or exciting term...)