From Audi 100 to urS4 in a week

[newsh]

Yeah, pics are fine for me too, it must be a Dave thing

[newsh]

Anyway, looks like they're socketed? Are those white plastic things retaining clips for the chips?

[hunker7]

Anyway, looks like they're socketed? Are those white plastic things retaining clips for the chips?

Indeed it is

[hunker7]

Can it be the fuel chip that is gone wrong?

[igor136]

Prj told me: Your "problem" has nothing to do with the ECU. People are always quick to blame that which they do not understand.

[hunker7]

Well then how does he explain that fuel consumption is 13mpg with one ecu, and 20mpg with the second one?

[igor136]

Let me start from the beginning.

I have/had 2 issues with my red S4;

• Bad fuel economy (14mpg around town)
• Not going over 4000rpm in 5th/6th gear

I thought, that bad fuel economy is down to the fact that it's not running properly.

NOW!!!

Yesterday I took ECU out of the grey S4, and put it into my red S4 and went for a test drive, so 3 things I noticed

• Fuel economy was inproved drastically (18-20mpg)
• ..but car still won't go past 4000 rpm in 5th/6th
• and car takes longer to boost, but still boosts to 1.9bar

That is normal first 100 km, same thing on my car

[hunker7]

That is normal first 100 km, same thing on my car

I know. Original ECU returned 13-15mpg

[Dift]

Over how many miles did you test your new MPG?

Anything less than a half tank I would take with a massive pinch of salt! We are only talking 5 MPG.

The error for a 5MPG difference could be driver, weather ECU re-learning (if the motronic does that) etc.

Your data sample needs to be at least a tank brim to brim (calculated not from the OBC).

[hunker7]

Over how many miles did you test your new MPG?

Anything less than a half tank I would take with a massive pinch of salt! We are only talking 5 MPG.

The error for a 5MPG difference could be driver, weather ECU re-learning (if the motronic does that) etc.

Your data sample needs to be at least a tank brim to brim (calculated not from the OBC).

It wasn't a lot. But on original ECU even driving carefully for many miles it averaged 13-15mpg. I will leave it in for now, and see what happens, but it's definitely an improvement.

[igor136]

Can you take maf, lambda from another car?

[hunker7]

Can you take maf, lambda from another car?

Have had different MAF on mine, and I already replaced lambda.

[UrS4boy]

BETTER?

Yes. Proper photo formatting with no "url", ".html" or "/url", just [img] then for image's url at photobucket and then [/img].

Finally I can see that ECU in the photo, was socketted at the factory and than the MAP sensor is the stock AAN 250 kPa (2.5 Bar) sensor.

[UrS4boy]

Your data sample needs to be at least a tank brim to brim (calculated not from the OBC).

the OBC is not that accurate, especially after only a few kilometers.

[hunker7]

Yes. Proper photo formatting with no "url", ".html" or "/url", just [img] then for image's url at photobucket and then [/img].

Finally I can see that ECU in the photo, was socketted at the factory and than the MAP sensor is the stock AAN 250 kPa (2.5 Bar) sensor.

Will change it ftom now

So, is it possible that fuel chip is bad? Has that ever happened?