LMM - Target vs. Actual

Hello everyone,

I have the Pierburg mass airflow sensor (MAF) in my 1Z engine. Is the value of 847.9 mg/R correct? I did a test drive yesterday and recorded the data using VAG Scope. The actual value was generally slightly above the target value, except during strong acceleration, in which case both values always coincided exactly at 847.9 mg/R.

Is that okay? I cleaned the catalytic converter a week ago (mileage at that point was 152,000 km) because I suspected it might be causing the engine to misfire.

I'm assuming that the conversion of the resistance values only applies up to a maximum of 847.9 mg/R, but I'd rather just check to be sure.

PS: What exactly does mg/R mean? Milli grams per R - although I have no idea what "R" stands for. I would have interpreted "H" as "Hub," but the VAG-Com software says "mg/R."

Thank you!

Hello, yes, R = Hub is correct!!

I have also wondered how they come up with the "R"!

"That's quite funny! Here's my guess: And by "hub," does it mean the hub of a single cylinder, or the hub of all four cylinders (1896 ccm)? If it's the latter, then "R" might stand for "Round," as the camshaft rotates once while all four cylinders are "lifting."

R is English and translates to H .

Actually, it is called "revolution" .

The LMM value of 847.9 is also correct, as you can see from my logs.

If your system's "IST" value (actual value) at partial load exceeds the specified "UEBR" (upper limit for exhaust gas recirculation), you "typically" have a clogged EGR valve.
The same applies to me.

The setpoint matches the actual value even at full load.

The question is simply how much the typical waste output is for you, exceeding 3000.

I've already posted quite a few logs about this as well.

If the score is significantly below 700, I would recommend running the same test again and logging data for group 010. If the amount of air reported is too low, the value of 4 in 010 (the Russian border area) will cause a problem.

Then it's time for a new mass airflow sensor (MAF) or an Ulfs 22 kOhm patch - see the technical article about "Pierburg MAF".

You can get those parts from VW for 80 euros as a replacement, which is a bargain compared to before.

m;

"A clogged EGR valve is something I can definitely imagine - I replaced my injector needle lift sensor (the entire injector body for the third injector) today, and the old injector was so incredibly dirty that I can't believe it's really good for my engine (and it feels that way when I drive it)."

What should I do now? Should I try to verschandeln it somehow, or should I just shut it down completely? Does the latter have any disadvantages for the engine or performance?

There is enough text here about how to disable the AGR (Abgasrückführung).

But cleaning is always worth it - okay, if you don't disable it, the dirt will be back quickly .

Why did you only replace one nozzle???

Did you hear any difference (between the old nozzle and the new nozzle)?

m;

The needle lift injector has always been "not working correctly" (see www.tdi-ruckeln.de) - I have now replaced it because the car is currently experiencing extreme "episodes," and I was able to get this injector assembly at a good price.

I also considered whether I should replace all four injectors at 152,000 km, but the price of almost 100 euros per "standard" injector (which would be almost 300 euros extra) meant that I only replaced the third one for now.

I'll take a look at the AGR at the earliest opportunity.

@tino

What you can/should do is simply read and finally use the search function. Whatever you want to know has been asked and answered thousands of times here, in this or slightly modified form. Can you remember when you registered? You agreed that you would only post after having done some reading, reading, reading. Based on the threads you've posted, it seems like you haven't done that.

/viewtopic.php?t=5367

...and here's another one who refuses to believe that the ESP (Mengestellwerk) might have a problem...

Naturally, changing only one injector will further exacerbate the uneven running of an engine.
Similarly, it's usually not recommended to replace only a single shock absorber.

Bertil wrote:

... and here's the next person who doesn't want to believe that the ESP (Mengestellwerk) might have a problem...

Okay, it really boils down to a cost issue. The NHG (likely referring to a specific system or component) has always been flawed, and now it had to be replaced. You're also right about replacing all four nozzles – that's something I asked about about a week ago. The uneven engine running is definitely present (more so than before), but my primary focus right now is to eliminate the jerking/stuttering.

I will now (reluctantly) search for the "Megenstellwerk" and perform the test with the speed controller.

Tino.