Modified URS6 running rich

[S4Marc]

When the car was mapped is the ECU left to its own program in closed loop? Eg they would only alter ECU settings in the open loop area

We know that the car is rich
We know that the lambda is telling the ECU it's rich
But the ECU seems incapable of reducing injector times to alleviate the issue

Let's say I fitted smaller injectors (440cc) would the ECU be able to control them in a closed loop scenario?

[S4Marc]

Thats the chemical ideal so anything numerically less is richer and vice versa.
Still a bit confused why its pulling so much vac compared to stock specs of 0.5bar difference between atmo and vac. Although that does help somewhat.
The point I was making earlier was how the test is conducted. You would have more chance at lower revs to pass if the maf is out of whack although I am not sure how much influence you can have on the testing procedure.
As you have said its a bit frustrating if you have evidence it has been capable of holding the correct value via the dyno print out. It appears to be leak free, the maf has been swopped with a relatively fresh one, can't see there being an issue with rpm sensing so that leaves the lambda itself which you have replaced and appears to be functioning. The mapping cannot go bad and ultimately relies on the signals already mentioned unless I have misunderstood how it works.

The reason my Fpr readings are 1bar different is because I manually pulled a vacuum

The cars inlet manifold pulls less vacuum

[twoqu]

It would have been useful to see what the car pulls in terms of vac, hopefully the 0.5bar that would be expected. That was one of the potential issues.
I suppose the logic behind putting back to near stock is its low cost compared to buying unnecessary components and it would prove that the components on the car allowed it to meet the emissions and get a ticket. If that was successful it would leave the injectors or the mapping as suspects if its unsuccessful we are back to square one!

[prj]

No need to do anything with the pressure, it's irrelevant, once they bring it up to fast idle, the pressure will be in-spec even with the 044. IDK why you guys are obsessing over pressure on idle, unless you put a stock pump in there it won't flow enough return. I mean yeah you can fit an aeromotive regulator there for example to have more return but what's the point when your map is not done for it.
ECU is closed loop based on load, which on a standard code ECU is MAF/RPM.
Either those tables are reduced a lot, or your MAF is out of spec, simple as that. Given the fact that at some point it worked most likely it's not the mapping.
All this info can be found on the m232.org wiki btw.

if you're throwing lambda codes it'll be out as well, any DTC's in the ECU? Have you even checked?

[S4Marc]

No need to do anything with the pressure, it's irrelevant, once they bring it up to fast idle, the pressure will be in-spec even with the 044. IDK why you guys are obsessing over pressure on idle, unless you put a stock pump in there it won't flow enough return. I mean yeah you can fit an aeromotive regulator there for example to have more return but what's the point when your map is not done for it.
ECU is closed loop based on load, which on a standard code ECU is MAF/RPM.
Either those tables are reduced a lot, or your MAF is out of spec, simple as that. Given the fact that at some point it worked most likely it's not the mapping.
All this info can be found on the m232.org wiki btw.

if you're throwing lambda codes it'll be out as well, any DTC's in the ECU? Have you even checked?

Only DTC is 00537

One would assume it's lower limit

[prj]

Assumption is the mother of all ****ups.

It is also possible your lambda is dead/dying, it sees lean all the time, and makes it rich into oblivion
Anyway, Block 000 data:


2 - Engine LOAD (KFUN*MAF/RPM = LOAD) Should around 22-24 on AAN/ABY and 18-20 on ADU on hot idle with AC off.
8 - Current lambda control (STFT), should be jumping up and down. It's a factor. X/128 - so 128 is 1, 64 is 0.5 or -50% fuel.
9 - Lambda adaptation (LTFT), this is the learned LTFT value. I've killed this on prjmod since it affects openloop too and has potential to explode your engine. But this is also a factor X/128.

Post the screenshot of this on hot idle.

[Thecrispynoodle]

Not read every page here but will share that my own rrunning rich condition was caused by worn mismatched injectors. O2 riches mixture up on the good ones because of the oxygen in the exhaust from the leanest one.

[S4Marc]

Not read every page here but will share that my own rrunning rich condition was caused by worn mismatched injectors. O2 riches mixture up on the good ones because of the oxygen in the exhaust from the leanest one.

What injectors where they? Deka ones?

[S4Marc]

Assumption is the mother of all ****ups.

It is also possible your lambda is dead/dying, it sees lean all the time, and makes it rich into oblivion
Anyway, Block 000 data:


2 - Engine LOAD (KFUN*MAF/RPM = LOAD) Should around 22-24 on AAN/ABY and 18-20 on ADU on hot idle with AC off.
8 - Current lambda control (STFT), should be jumping up and down. It's a factor. X/128 - so 128 is 1, 64 is 0.5 or -50% fuel.
9 - Lambda adaptation (LTFT), this is the learned LTFT value. I've killed this on prjmod since it affects openloop too and has potential to explode your engine. But this is also a factor X/128.

Post the screenshot of this on hot idle.

VCDS lite doesn't seem to be able to access block 000, think I need to purchase the full version

Will try VagCom 409 when I get home later

[Thecrispynoodle]

Also there is s reference to an 044 pump here. If you have a new FPR these have a smaller return outlet than the original and can’t return enough fuel because of the increased delivery of the 044 causing excess FP at idle. Try a good working ORIGINAL 4.0 bar. What’s also odd is you are not getting a 561 DTC which suggests ecu doesn’t actually think there’s a problem.....

[Thecrispynoodle]

What injectors where they? Deka ones?

OEM. I swapped in good red Bosch Volvo injectors these are close enough in spec to OEM for ecu to reign the difference in.

[prj]

Not read every page here but will share that my own rrunning rich condition was caused by worn mismatched injectors. O2 riches mixture up on the good ones because of the oxygen in the exhaust from the leanest one.

It doesn't work that way.

Lambda value is average across all cylinders. So some cylinders will be rich, some will be lean. His problem has nothing to do with it.

Also there is s reference to an 044 pump here. If you have a new FPR these have a smaller return outlet than the original and can’t return enough fuel because of the increased delivery of the 044 causing excess FP at idle. Try a good working ORIGINAL 4.0 bar. What’s also odd is you are not getting a 561 DTC which suggests ecu doesn’t actually think there’s a problem.....

Doesn't matter which standard type regulator you use, it's not going to have enough return for a 044.

Yet more misinformation.

[S4Marc]

It doesn't work that way.

Lambda value is average across all cylinders. So some cylinders will be rich, some will be lean. His problem has nothing to do with it.


Doesn't matter which standard type regulator you use, it's not going to have enough return for a 044.

Yet more misinformation.

This is something I have now proved that the standard FPR can't return enough, PRJ did already know this

An aftermarket aeromotive FPR can return more (I used a Sytec 1:1)

[Thecrispynoodle]

This is something I have now proved that the standard FPR can't return enough, PRJ did already know this

An aftermarket aeromotive FPR can return more (I used a Sytec 1:1)

You can also drill out the return on a stock FPR to increase return flow.

[twoqu]

The reasoning behind albeit temporarily getting the fuel pressure down is to get the car back to as stock condition as possible for the MOT test. Ideally we would want the stock fuel pressure, stock injectors, stock sw and a maf that based on its history is still within spec. That gives us the maximum chance of success.
It is a good opportunity to get a base comparsion via VCDS between the two mafs which I have suggested previously. If the OP tested the ecu to see what resistor it has then we would know which range was applicable. Not that it makes a lot of dfference as the factory specs are 15-24 for ADU and 20-26 for AAN then anything above the top limits suggests the maf.
I understand the lambda is a new replacement.