AUDI A2 1.6 FSI 2002 Throttle Body part no 036133062D seems to be discontinued

So I got four injectors reconditioned by an expert and they have been fitted to the car and the car is still the same. The mechanic is now talking about there is lower compression on cylinders 1 and 2 than 3 on 4 with the new injectors in and he is talking about the various possible causes of that. He said on early FSI engines like this you cannot switch of the misfire counter so that is still producing the error codes. He said his most valued employee a younger guy who is a mechanic has done a lot of tests on the car. They are suggesting to take the engine apart and to clean various valves associated with the cylinders but they are worried they might find Bore Score in Cylinders 1 and 2 also. This will cost a lot of money to take the engine apart right down to cylinders.

I thought that Bore Score in cylinders could be viewed by sticking a Bore Scope through the spark plug holes. Is this possible please on an Audi A2 FSI Petrol 1.6 or do you have to take the engine out. Perhaps the younger mechanic has done this but what if he hasn't! If there is bore score in cylinder 1 and 2 is there any simple fix here like putting thicker oil in like you would on a Porsche or is this 1.6 FSI engine a poor respondent on that old trick. Plus I saw an article which said you cannot get larger pistons for the Audi 1.6 FSI which makes a re bore almost impossible.
 
I’m not sure what your mechanic is talking about. Switching off the misfire counter wouldn’t solve the issue, it would just hide the problem? And it’s not really something you can “switch off” anyway, you can only stop the ECU generating the code.

You can borescope the engine through the spark plug holes and see marks in the cylinder if there are any

EDIT: I realise on some 1.4’s, and maybe 1.6? they can be more sensitive to certain codes. But even still, disabling fault codes is a very extreme step
 
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The egr pipe is known to crack and cause air leakage. It would be worth checking this part perhaps.

Do you notice a change in the engine running when you remove the oil cap on the car.

You should expect it to change the engine running instantly when taking the oil cap off the engine if you have a good vacuum in the engine.

Sorry this is just some off the cuff advise. I really hope you manage to make some progress soon and wish you luck.

Low compression though? This is confusing if it wasn't an issue before?
 
The car needs vcds logging while being driven, with varying engine speeds and loads.
DTCs point you in the direction of the problem, but then you need dynamic data to narrow it down, hence my query on MoT status.
Mac.
 
Thanks for these replies yes MOT still good to July 24. Funny you should mention the EGF Pipe because that was broken some how during these procedures I imagine and I was asked to get another one which I did and that has been put on the car now. I will try the oil cap thing.

I think with the compression the mechanic had that down as a problem early on he knew that Cylinders 1 and 2 were not performing as well as Cylinders 3 and 4 on compression and he thought it might be the injectors on cylinders 1 and 2. Another thing is the engine has always had a tappet type sound like lifter tick or like a diesel engine and I know that this is the sound associated with bore score. Not sure he has tested the oil.

The mechanic will take it on a test drive next with diagnostics plugged in.

The misfire counter counts hundreds of misfires in a few seconds on the car and then the ECU reacts to that which means you can't drive it 3 seconds after you turn on the engine and you cannot switch that counter off on an early FSI engine. On later FSI engines you can turn off a misfire counter and there is a good reason for this it's so you can drive your car and get more meaningful analysis codes on a test drive when your car does actually go wrong on that test drive or if it doesn't go wrong then you know that it was the counter and the ECU that made your car switch off. Its like limp home mode great it stops your car blowing up and gets you home but when you know there is something wrong with your car and limp home mode happens every time you try to test the car when your fixing it how does that help find out whats wrong with your car? What I'm saying is me you everyone on this forum knows this car is broken and so does my mechanic so how does it help us now if the car counts 300 misfires lights up on the dash like a Christmas tree with every light on there and switches off. We can't test the car or find the faults.
 
By the way the mechanic thinks FSI engines are prone to carbon build up in the back of the intake valves and he wants to take the whole engine apart again and clean them up.

Could it all just be the HPFP I have replaced this before and earlier in this conversation I said I didn't think it was because the problem is so specific to cylinders 1 and 2 but I found this post on here which I will quote in my next post with someone who had cylinder specific problems which went away after a HPFP change. What codes does the HPFP give when it is loosing pressure please or not delivering enough pressure or is it possible it would not give any codes at all
 
example forum of a low compression on specific cylinders being fixed by a replacement HPFP

The Misfire Struggle (1.6 FSI - BAD)​

The Misfire Struggle (1.6 FSI - BAD)

Hi everyone, I'm Julian I live in France (Strasbourg) and I'm living a nightmare with the famous misfire issue on the A2s. Here is my story. I bought an A2 1.6 FSI - 2003 - 98 000 km - Engine code : BAD last month for 1 500€ knowing it had the orange engine light ON (not flashing). Prior to...
www.a2oc.net www.a2oc.net

 
Lots of parts have been changed, at significant expense, sometimes based on a DTC, and sometimes on. "mechanic's intuition" and without fixing the problem.
There is a lack, (a total absence even), of measurements and diagnostic data.
A good example is the replacement of the HPFP, and the electric lift pump. The efficiency of both of these can be checked by logging measuring blocks, during a varied drive, let's say 15 - 20 minutes, plus analysis. This will give a result with a high degree of certainty. But no, let's spend hours of costly labour, and change both.
To diagnose most running engine faults on an FSI, the only effective way is to log relavant data, and analyse it.
As far as I can understand, at no time had this been considered.
Now, it seems changing the HPFP is being considered again. For goodness sake, check it out first.
I don't doubt your mechanic's skills and experience, but he needs to use "virtual" tools, as well as the chrome vanadium ones.
Log Groups 005, (to monitor engine speed and load), 140, (to check fuel rail pressure), and 142, (to check the inlet manifold flaps). No gaurentees, but it'll rule a few things in, or out, which would be progress, in my opinion anyway.
You may need to get yourself a working, registered copy of VCDS Lite, and a KKL lead. Any old Windows laptop, lead at a tenner, and $99 to register Lite is all that is required. The lot would cost less than the labour to change the pump, I suspect.
Mac.
PS: No offence intended to anyone.
 
Sorry I also did not mean to cause offence. I do not own an FSI, however, I have not heard of one misfiring so bad that the ECU switches the engine off.

Normally the engine would run still, and you would have a blinking engine management light. When you read the codes, you can just ignore the misfire related ones.
Turning off the misfire counter is, to the best of my knowledge, still only something that could be done be by the same process as a remap and if it was the misfire was so bad that you needed to do that, the car would be undriveable in anyway.

I’ve just noticed you said “dash lights up like a Christmas tree with every light on”, is that an exaggeration? If not, you have more issues than the misfire

Will be interesting to see the results of the logging if they can be shared
 
Yes I take your point about the VCDS @PlasticMac however as we have discussed before the mechanic only gets P300, P3001, P3002. I personally do not understand how VCDS works and nor do I have the system myself. If is absolutely correct what you say the car has had second hand parts bolted to it and the injectors are the only reconditioned parts.

I think I've asked you before @PlasticMac if I can get this car to someone on this site who is a proper mechanic and who can do these tests in the detail you say I just would not be having these problems most likely but the reality is I'd have to get this car towed to that location. Another possibility is the mechanic has got VCDS and I will just need to go through it with him. I have never been in a situation with this mechanic like I am in at the moment where he can't fix a car. I've said it before I have got the money, the mechanic has fixed other German complex cars e.g. I have a 1997 BMW 540i he has been fixing that since 2009. However the Audi A2 1.6 FSI is just another level of complicated.

So your saying plugging in the VCDS and getting no fault codes for Throttle Body and HPFP isn't the end of the story you can analyze further using VCDS and possible still find that there is something wrong with these parts while they are on the car?

@a-zwo no worries yeh lets say you start the car and its doing 1200 rpm to make this calculation easy then the counter will get to 200 misfires in 5 seconds I guess with 2 cylinders misfiring.......I'm hoping its better than that now hence the test drive
 
Your mechanic is simply scanning for stored fault codes. These are faults recorded by the ECU, typically, while the car is be driven, which means the ECU saw data from a sensor, or sensors, that the ECU interpreted as a fault condition, and so stored a code.
The conditions, (sensors), behind that code are dynamic, and, in most cases, only present when the engine is running, and then, only under specific engine loads and speeds.
The only way to identify those transient conditions is to log, (save a continuous data set), of the sensor readings most likely to be related to the static stored code.

VCDS is a software tool that, the in addition to giving you those static fault codes, can also log sensor data, in real time while you drive.
One such data set continuously records the actual fuel rail pressure, (injector feed), and the fuel rail pressure requested by the ECU.
These two pieces of information will show if the fuel pumps, and the fuel pressure control system is working correctly. So at the end of a 15 - 20 minute run, you'll have a data set to rule fuel system in, or out, as the likely culprit.
Help with the analysis is available here.
If the fuel system looks good, then we can move on to the next suspect, logging a different data set
Hope this gives you a bit of insight into why I waffle on so much about VCDS and data logging.
Mac.
 
@PlasticMac thanks so much for this. this sounds good the mechanic thinks he has got the car to the point where he can do a twenty mile test drive in it I will check with him that he is going to do in terms of logging faults he can analyse later;

Windows Based VAG/VAS Emulator Running on Windows 10 x 64 VCDS Version Release 21.3.0 (64X) Data Version 20210226 DS325.0 as of July 2021

is that good enough if he has had updates and upgrades please?
 
I think so. But I only have VCDS Lite, not the full version. Hopefully, another member can confirm.
It's very important to check that the folder named
"Labels" has a file named 036-906-013-BAD.LBL or 036-906-013-BAD.CBL
This is an FSI specific file, which has only recently been added to the full version of VCDS, which is, I think what your mechanic has.
I'll tag @Andrew and as he has a full version, he can confirm my thoughts.
I would log Groups 005,140 & 142.
These links explains more about how to log with VCDS:
Good luck.
Mac.


 
PhilipS said:
@PlasticMac thanks so much for this. this sounds good the mechanic thinks he has got the car to the point where he can do a twenty mile test drive in it I will check with him that he is going to do in terms of logging faults he can analyse later;

Windows Based VAG/VAS Emulator Running on Windows 10 x 64 VCDS Version Release 21.3.0 (64X) Data Version 20210226 DS325.0 as of July 2021

is that good enough if he has had updates and upgrades please?
Click to expand...
Good Evening,

Release 21.3.0,would have been early 2021. In the Spring of 2023 there was a update of a completely new label file addition specifically for the FSI BAD engine, a major improvement with monitoring measuring Groups which I suspect your mechanic is not seeing. I strongly suggest the current release of VCDS is 23.11.0 is downloaded.

Andy
 
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If, for some reason, he can't update, the A2OC's version of the FSI lbl file can be downloaded here:

FSI ECU VCDS Label File Add-In Download

Attached something never before available to my knowledge¹, a VCDS label file for the FSI ECU in English. This file can be used with all versions of VCDS, Lite (Registered or Unregistered) or Full. Prior to this point the text that appears with FSI VCDS ECU Measuring and Basic Settings groups...
www.a2oc.net www.a2oc.net
Mac.
 
I've got the car back it just has a flashing yellow warning light on when its stationary and running then when I drive it the yellow light is solid. The car starts drives fine but I have not taken it on a motorway yet or driven at over about 45mph. @PlasticMac please give me the name of a company who can perform a full analysis on it I live in Bedfordshire so it would be better if the company was either in Luton or near there.

In terms of mechanical checks no bore checks have been done but every other check has
 
PhilipS said:
I've got the car back it just has a flashing yellow warning light on when its stationary and running then when I drive it the yellow light is solid. The car starts drives fine but I have not taken it on a motorway yet or driven at over about 45mph. @PlasticMac please give me the name of a company who can perform a full analysis on it I live in Bedfordshire so it would be better if the company was either in Luton or near there.

In terms of mechanical checks no bore checks have been done but every other check has
Click to expand...
Is it the yellow light with an engine shape?
A simple scan of the engine would be a good place to start.
Looking at the free scan register, @A2Dreamer is not too far away. Worth a PM.
I'd suggest we start from a clean sheet, so much history, that it's hard to pick up any common thread.
Happy to liase with you, and anyone with VCDS who can help.
Will share WApp, for real, (ish), time support.
Good luck.
Mac.
 
@Crgwal You asked 'Do you notice a change in the engine running when you remove the oil cap on the car.' Yes I do it goes from a normal engine sound to an engine that is spluttering and going to cut out. Then when I put the oil cap back on the engine noise returns to normal
 
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