1Z Engine: Misfires and Jerking - Troubleshooting

Hello.
Okay, I'm quite new to this forum, and I've already done some research online and read about the issues of jerking and misfires with the 1Z engine.
I've already tried reading the error codes, but nothing seems to help me figure it out.
It's possible that multiple parts are defective.

Okay, first of all, here's the description of the problem:
1. During the warm-up phase, there's a jerk when shifting up around 2500 RPM, but only when shifting into second gear.
(This reminds me of a needle valve.)
2. Short, sporadic engine cutouts, occurring while driving uphill on the highway under full load, in a warm engine condition. There was a slight loss of power beforehand, followed by a return to normal power.

Then I took it to a workshop and had the error codes read.
The result indicated sporadic implausible speed signals and intermittent incorrect boost pressure readings (I've forgotten the exact wording now).
They said to replace the mass airflow sensor.
But if the signal from the mass airflow sensor is incorrect, wouldn't the fault memory indicate that specifically?

Then I read about all the other possibilities and didn't want to spend forever replacing parts that weren't actually defective. Besides, the parts that might be the problem aren't exactly cheap.
So, is it a needle valve actuator, a mass airflow sensor, a boost pressure regulator, or something else?

I would be grateful if someone could give me more specific feedback on the errors.

Greetings.

Hello,

It's highly likely the needle valve actuator. Perform this test at idle: Have someone set the engine speed to 3000 RPM, and then tap the needle valve actuator with a screwdriver or similar tool. If the engine jerks, you've found it with 100% certainty.

Best regards,
Albrecht.

Okay, I've done that before.
But nothing happened.

except that I noticed that when you reach 3000 RPM, even with a constant throttle position, it first drops back down by about 400 RPM.

I'm not sure if the testing method is that reliable.

Greetings.

Hello,

So, a friend of mine who owned a similar car also experienced these intermittent issues on the highway, and we were able to reproduce them quite well using the knocking test.
You definitely have to hit it quite hard, and not just once, but several times in a row. And the problem doesn't happen constantly while driving!
certainly:

Quote:

2. short, sporadic engine cutouts, occurring in warm conditions under full load while driving uphill on the highway.

It sounds clearly like a needle injector to me.

Best regards,
Albrecht.

I've already knocked on it hard and often.
Nothing happened, everything ran normally.

Greetings.

Please always include the mileage and model . It's great that VW wants to make a profit again and wants to replace things without a plan...

That looks good: [Link]. Let me give you another letter and compare the cable length .

Wow, I was also thinking of getting that as a spare part. *g*

Best regards, WarLord.

Hello,

I saw it on eBay, but it was too expensive and already sold.

Passat model, 1Z engine, 205,000 km.

So, when you tap on it, the motor continues to run normally.
I tried it again.

However, I also noticed that when I'm driving and release the accelerator pedal, wait a moment, and then press the accelerator again, there's a slight hesitation or jerk twice.

Workshops are .

'The carbureted vehicles I used to have, I haven't seen any more of. I prefer to do everything myself, and I've never really had any problems.'

But with the TDI, you start having problems right from the error memory.

Greetings.


Greetings.

Hi,

I'm familiar with this problem, although it's a bit more extreme in my case, specifically within the engine's RPM range. After trying various solutions and possibilities, I'm now convinced that, at least in my car, it's likely a worn-out mass airflow sensor (MAF sensor) for the ESP system.
A diesel fuel system cleaner (which, in your case, would be a diesel flush) might help remove the deposits. Unfortunately, it didn't work for me.

So far, the following parts have been replaced: engine mount, mass airflow sensor (MAF sensor), and solenoid valve (which was actually defective!).
Settings (measurement blocks according to the DIY vibration dampening guide -->/viewtopic.php?t=658).
With a pump mileage of 370,000 km, I think that's probably within the acceptable range. I'm living with the occasional jerking and I appreciate every stretch of road where it doesn't happen.

Does the shaking stop when you go above 140 km/h?

Klaus.
09/94, TDI, 1Z.

Hello,

I would approach it like this:
- Relay 109, is it okay?
- Check the wiring harnesses and connectors for the ESP (Electronic Stability Program) system. Inspect them visually, test their continuity, and check for any loose connections.
- Transmitter position feedback module, which version? Poti (potentiometer - bad) or HDK?
- Wie alt sind die Einspritzdüsen? Dripping?

Best regards, Rainer.

Hello,

Everything has been checked.
LMM is still showing good values; it seems to have been replaced before, as it has '98' printed on it.

Okay, I just bought a new needle gauge for 190 euros! Yay!
And the remaining nozzles will be tested to see if they are sealed properly.
If that doesn't help, then
But then, at least that rules out a problem with the piston.

Okay, mine still has those intermittent issues even at 160 km/h.


Greetings.

Rainer K. wrote:

Hello, I would approach it like this: - Relay 109, is it okay? - Check the wiring harnesses and connectors for the ESP (Electronic Stability Program) system. Inspect them visually, test their continuity, and check for any loose connections. - Donor position, quantity control device, which version? Poti (bad) or HDK? - Wie alt sind die Einspritzdüsen? Dripping? Greetings, Rainer

Hello,

I'm new here and I'm also experiencing occasional, severe jolts while driving on the highway, which are more than just minor stutters. Otherwise, I think the engine is running fine (it's my first TDI), with no loss of power or anything like that.

The car is a G3 TDI, engine code 1Z, first registered in 04/1994, with 220,000 km on the odometer.

I checked the relay 109 for the first time just now, and that's already leading to my question:

Is it normal for this relay to get so hot that you can't really touch it with your fingers about 1.5 minutes after turning off the engine?
Surely, that can't be right?

I thank you in advance for all responses.

Best regards,
Oliver.


/edit: I hope it's not a problem that I've added my post to this older thread, but there are certainly already enough threads about the 1Z and its problems.

@TDI-Victim
I'm having the exact same problem as you!
So far, the problem has only occurred very rarely, which hasn't bothered me too much.
But recently, it has been happening more and more often .
And on my way home today, I saw a very dense cloud of black smoke in the rearview mirror while the car was momentarily stalled.
It's time to do something.

A quick question: Can the NHG (presumably a specific component) be replaced separately, or would I need to buy new ESD (Electrostatic Discharge) protection devices?

hello,

Is the final speed correct?
My 1Z had the same symptoms!
It only ran at 160 [units/speed/etc.] then.
The needle firing system has been replaced, and now it's working again like a Pershing II.
By the way, it's only available as a complete set with the nozzle.
But the trade is really worth it.

mercy1960 wrote:

Is the final velocity correct?

Yes, it will still be achieved.
But then I'll probably buy all the nozzles right away because the engine is already running quite rough, and I'm hoping it's related to the ESD (exhaust system).
Another 400€ gone .