Timing Belt Replacement & Chip Tuning Services

Hello everyone,

Soon, the timing belt on my 1.4 AMF engine needs to be replaced, and I'm having it done at VW this time. The car has been chipped for almost 40,000 km, and since the injection timing will be checked and possibly readjusted using a diagnostic tool after the belt replacement, I wanted to ask if these adjustments would affect the chip tuning? Or is there no interference in that regard?

Thank you in advance for your information!

Regards,

Mark.

Hello. I also had a timing belt replacement done on my Chiptuned car. Since this question was also concerning me, I called my tuner (********), and he said that it's not a problem because the chip has the data permanently stored.
However, this can be a problem when the EEPROM has been flashed via OBD II.

So, to cut a long story short.
Nothing has changed.

So, can I understand from your statement that the newly soldered EEPROMs are not flash-EEPROMs and therefore cannot be altered via OBD2 (*** was also soldered on mine)? I find this strange because ultimately, when adjusting the data during a timing belt change, the new data wouldn't be saved either, or is there another rewritable memory chip on the circuit board?

The memory is called EEPROM. It stores things like error logs.

Best regards, Rudi.

'But they can mechanically adjust the start of injection, and then no chip is effective. This is something I've never thought about before. Who can provide reliable information on this, and how should one approach a workshop regarding this issue?'

hi,
In both AMF and all PD engines, the camshaft is adjusted mechanically during the timing belt replacement.
There is no electrical adjustment.
If the timing belt replacement was done correctly, the settings will be exactly as they were originally.

I don't quite understand the question. With a correct setting, the injection timing should be within a certain tolerance range. If, after replacing the timing belt, the injection timing is adjusted back to the engine's original values, then everything is fine. However, if it's not adjusted correctly, you'll have a problem regardless of whether or not you have chip tuning.
You can check the injection timing with VAGCOM, and if it's incorrect after being changed, the workshop needs to readjust it.

Workshops often have problems with 'properly adjusting' things, as you can frequently read in discussions like this.

CU Gremlin.

x world one wrote:

I don't quite understand the question. The injection timing should be within a certain tolerance range when properly adjusted. If, after replacing the timing belt, the injection timing is correctly readjusted to the engine's specifications, then it's perfectly fine. However, if that adjustment isn't made, you'll have a problem anyway, whether or not you have chip tuning. You can check the injection start timing with VAGCOM, and if it's incorrect after a change, the workshop needs to readjust it.

Hi,

PowerSound is right.
In the case of pressure distributors (which is what we're talking about here), it's not possible to control the actual injection start time.
If it's supposed to start, the engine control unit only provides power to the PDE (pre-injection device), but it doesn't detect whether the high-pressure side can already build up enough pressure to initiate the injection.

"With my engine that was incorrectly configured from the factory, all the VAGCOM values were fine, but it was lacking about 10 horsepower. This was likely because the fuel injection started too late."

Thank you for the answers! So, I'm just worried again about whether they can actually get the mechanical adjustment right (I've read quite a bit about this in the forum).

Now, all I need to do is find a reasonably priced VAG workshop, because I think €568 just for the timing belt replacement (including parts) is quite expensive.

ulf wrote:

Hi, PowerSound is right. In the case of pressure distributors (which is what we're talking about here), it's not possible to control the actual injection start time. If it's supposed to start, the engine control unit only provides power to the PDE (pre-injection device), but it doesn't detect whether the high-pressure side can already build up enough pressure to initiate the injection. My engine, which was incorrectly configured from the factory, had all VAGCOM values within the normal range, but it lacked approximately 10 horsepower.

This was likely because the injection timing started too late. }

Hi Ulf,

Oh, I see, that makes sense. But I really can't imagine that it's not possible to control this. There must be some way to do it, right?
The simplest approach would probably be to perform a DZR test before and after the change.

x world one wrote:

But I really can't imagine that it's not possible to control this. There must be some way to do it, right? The simplest option would probably be to have your DZR test done before and after the change.

... for example.
Or disconnect the zero-reference protection and perform a mechanical inspection according to the technical article.
As far as I know, there's nothing to check regarding the year 1551 or laptops.

That's a good question...

Does the VAG-COM diagnostic tool display the crankshaft position sensor anywhere? Specifically, does it show its timing relative to the crankshaft?

CU Gremlin.

As I said before: Nothing works with VAG-COM in this case, as far as I know.
I wouldn't panic about it. If you notice a drop in performance after the change, then I would investigate.
I had my last timing belt replacement done by a mechanic again (I didn't have the time, and given my resources, I would have had to remove the hood or acquire some kind of support device to lift the engine).
My independent workshop charged me 115 euros. I bought the parts myself from Volkswagen. In total, it cost me significantly less than 300 euros.
Once you've created the space (removed the air ducting) and removed the engine mount, adjusting the belt isn't that complicated according to the VW instructions. So, it doesn't necessarily have to be done by a VW workshop. However, the necessary specialized tools already cost around 60 euros (excluding an engine support device), so I would say that doing it yourself isn't worth it unless you drive extremely long distances. But I wouldn't let anyone do it for over 500 euros. If they're already quoting a price like that, there's a risk it will cost even more later on with a bit of bad luck.

Regards,

Olaf.

Gremlin wrote:

Does the VAG-COM display the phase sensor anywhere?

Or its timing in relation to the crankshaft?
Well, we've already pondered the meaning of the measurement called "synchronization angle" in various threads, but } without any logs from engines that were correctly and incorrectly configured, we haven't yet reached a definitive conclusion.

Someone once posted possible causes for values outside the tolerance range (likely from a VAG document). However, a misadjusted valve clearance was specifically not listed among them.