Wiered Fuel Injector Combination Problem

[conradha]

Hi Guys.. something weired needing you experts here to sort out and suggest.

I have an A3 8L 1.8T where the Engine code on the CAR LABEL is an AUM engine whicch is standard.

I've used Vagcom and the ECU reported that that engine code is AUM <-- meaning that the ECU is configured for AUM.

My finding is here,

I one day found out that there is an APU (checked that is for A4?) letter embosed on the engine, making me suspect (pretty sure actually) that the previous owner(s), might have swapped the engine for whatever reason.

Subsequently I found that the injector now used is:
V/W 035906149A / Bosch 0280150447 which spec is giving 210cc at 4 bar

vs
The standard one for AUM that I found out on web should be
V/W 06A906031BA / Bosch 0280156061 which spec is giving 314cc at 3 bar

so that is 210cc @ 4bar vs 314cc @ 3 bar?? thatz a HUGE difference. but the car seems to run without problem. . .

The problem is this,
no matter what, the Injector seems way off the spec, so does the use of injector should be be matching with the ECU (AUM) or should it be matching the Engine (APU)? I ask so beacause I am thinking of replacing the injectors to the aum spec ones.

What problem might variance in spec cause me? fuel efficiency / under power?
Think this way: 50% throttle = 105cc vs 33% throttle = 105cc <-- so I am constantly stepping deeping to overcome the deviance?

Please suggest.

 

[<tuffty/>]

Won't be an A4... completely different blocks (058 or 06B)... by embossed are you looking at the tab on the head? it could have had the head from an APU A4... all 20v heads are interchangeable so maybe needed a head swap at some point... I have an AEB head on my S3...

Injector details can be checked here
1.8T Injector Details Spreadsheet - SEAT Cupra.net - SEAT Forum

The 210cc ones look to have come from an AEB... seems you have a bit of a pick and mix of components on your car for whatever reason... fuelling should be ok for the std power but I suspect if you looked at block 032 in VCDS there may be a large positive figure in the long term fuel trims as the map will be scaled for 314cc @ 3bar not 210cc @ 4bar... is the FPR rated at 4bar or 3bar?

As your car is an AUM you could log blocks 001 to see if lambda is making big adjustments to add fuel, 031 to see if AFR is meeting request and view block 032 (no need to log) to see what the fuel trims are doing

<tuffty/>

 

[sideways steve]

The chances are the injectors off the original engine were kept and only the head was replaced swapping over all other parts, hence why it probably runs ok.

Surely the easiest solution here would be to check the part numbers on teh injectors to see whats fitted ? or are you saying you have already done that ? your post is a bit hard to understand lol !

 

[conradha]

The chances are the injectors off the original engine were kept and only the head was replaced swapping over all other parts, hence why it probably runs ok.

Surely the easiest solution here would be to check the part numbers on teh injectors to see whats fitted ? or are you saying you have already done that ? your post is a bit hard to understand lol !

Well, sorry for the messy post. probably because the situation there is actually a mess... haha.

You're right. I 've checked that the injectors are those are the 210cc ones.Not the ones supposed to be used on AUM engines.

Do you guys suggest me to switch to 314cc ones? will it do any harm, or the ECU will be smart to adapt that anyway?

 

[conradha]

Won't be an A4... completely different blocks (058 or 06B)... by embossed are you looking at the tab on the head? it could have had the head from an APU A4... all 20v heads are interchangeable so maybe needed a head swap at some point... I have an AEB head on my S3...

Injector details can be checked here
1.8T Injector Details Spreadsheet - SEAT Cupra.net - SEAT Forum

The 210cc ones look to have come from an AEB... seems you have a bit of a pick and mix of components on your car for whatever reason... fuelling should be ok for the std power but I suspect if you looked at block 032 in VCDS there may be a large positive figure in the long term fuel trims as the map will be scaled for 314cc @ 3bar not 210cc @ 4bar... is the FPR rated at 4bar or 3bar?

As your car is an AUM you could log blocks 001 to see if lambda is making big adjustments to add fuel, 031 to see if AFR is meeting request and view block 032 (no need to log) to see what the fuel trims are doing

<tuffty/>

Thanks for the reply mate, I will take a look as you said.
But would it be at some point (like when I step down to the bottom, the flow of the injector is high enough, so my power is limited?)

what about fuel consumption, will there be any influence? because I am thinking the that my fuel efficienyis pretty bad, i usually get around 300 - 320 km before the fuel meter go close to the red area.

 

[<tuffty/>]

Well, sorry for the messy post. probably because the situation there is actually a mess... haha.

You're right. I 've checked that the injectors are those are the 210cc ones.Not the ones supposed to be used on AUM engines.

Do you guys suggest me to switch to 314cc ones? will it do any harm, or the ECU will be smart to adapt that anyway?

The ECU will adapt to a degree but even at 4bar its only adding 15% flow over the 210cc and the ECU is scaled for 314cc @3bar... personally I would get them changed to 314's and make sure the FPR is 3bar

Thanks for the reply mate, I will take a look as you said.
But would it be at some point (like when I step down to the bottom, the flow of the injector is high enough, so my power is limited?)

what about fuel consumption, will there be any influence? because I am thinking the that my fuel efficienyis pretty bad, i usually get around 300 - 320 km before the fuel meter go close to the red area.

With smaller injectors the problems will be higher rpm fuelling under heavier loads... a full throttle acceleration run may go lean top end as you run out of injector flow... on a std tune (150hp) you 'should' be ok but I would be looking to get the correct injector/FPR setup back in sooner than later..

If the ECU is constantly adjusting to correct fuelling then this could affect MPG but tbh I would put it back to std (correct injectors/FPR... may have mentioned this a few times lol) then see where you are from there... it could be another problem but its best to eliminate/sort known issues first and it makes it easier to trace any others

<tuffty/>

 

[sideways steve]

Well if your ECU is the AUM one and its not been remapped than it thinks the injectors fitted are the 314cc ones so you should have no issues swapping them over. Just reset the ECU once you have swapped them so that your fuel trims will readapt and you should be good to go.

If your ECU has been remapped though, you may find they have compensated for the change in injectors and when you fit the 314's it may overfuel.

 

[conradha]

Well if your ECU is the AUM one and its not been remapped than it thinks the injectors fitted are the 314cc ones so you should have no issues swapping them over. Just reset the ECU once you have swapped them so that your fuel trims will readapt and you should be good to go.

If your ECU has been remapped though, you may find they have compensated for the change in injectors and when you fit the 314's it may overfuel.

How can I checked if they have been remapped? I guess not because the car is not that powerful though IMO. . . .

 

[conradha]

Won't be an A4... completely different blocks (058 or 06B)... by embossed are you looking at the tab on the head? it could have had the head from an APU A4... all 20v heads are interchangeable so maybe needed a head swap at some point... I have an AEB head on my S3...

Injector details can be checked here
The 210cc ones look to have come from an AEB... seems you have a bit of a pick and mix of components on your car for whatever reason... fuelling should be ok for the std power but I suspect if you looked at block 032 in VCDS there may be a large positive figure in the long term fuel trims as the map will be scaled for 314cc @ 3bar not 210cc @ 4bar... is the FPR rated at 4bar or 3bar?

As your car is an AUM you could log blocks 001 to see if lambda is making big adjustments to add fuel, 031 to see if AFR is meeting request and view block 032 (no need to log) to see what the fuel trims are doing

<tuffty/>

Thanks Tuffty,
So I will take a look as you said,

And do you think there will somehow be some affect in the performance? e.g. will the actual fuel output / flow now high enough when I step down to the bottom?? coz the flow rate isn't high enough, and will the difference in spraying pattern (if any) affect the performance??

but from your view do you think the wrong match of the fuel injector will affect my fuel economy? because I find my car's fuel consumption is pretty bad.

From a full tank, I am constantly running 300 -320 until the fuel meter goes really close to the read area.
Is that normal?

 

[<tuffty/>]

The early injectors won't have the same spray pattern or electrical response as the correct ones.. the map has provision to dial these characteristics in so calibration will be out and the ECU will be fighting to keep injector duty somewhere handy... this will of course affect MPG

Replacing the injectors should help but as I said there could be other issues contributing to your poor consumption...

<tuffty/>

 

[beachbuggy]

4 Bar FPR and AUM fuel pump wont be that happy I'd suggest also. Assuming you have a 4bar fpr fitted and not the 3 bar original.

 

[conradha]

Latest update. . . Found out that it is actually really a 4bar fpr and actually the injector is a Bosch 028156070 / vm# 06b 133 551n which is giving 252@3bar and 289@4bar

So what I have now is 289@4bar

Will changing back to original 314@3bar do any good???

Hi guys , experts please advise!!!

 

[<tuffty/>]

...Will changing back to original 314@3bar do any good???

Yes... do it..

<tuffty/>