Differences 3B to ABY, fueling

[newsh]

Are there any differences between the 3B and ABY apart from the obvious, that could cause fueling to be different?

Since the conversion the car runs lean on idle and rich on boost. It may be the mapping which has been estimated remotely but just checking all the bases. So could there be any difference between TPS, other sensors etc? I'm sure the MAF is the same and if it was a fuel restiction it would be more likely to run lean on boost.

[AndyP]

FPR is different, 3B is 3bar, ABY 4bar, this might explain the lean condition on boost.

http://forums.quattroworld.com/s4s6/msgs/21108.phtml

Edit - Mis-read your post, just saw the 'lean on boost' at the end

[newsh]

I've fitted an ABY fuel rail and 4 bar FPR.

If I let the car idle it will adapt over a couple of mins to run at 14.5 AFR. If I then drive the car it will run rich on cruise untill after a couple of mins it adapts and cruises at 14.5. Coming to a stop though it is really lean and stalls, it will then restart and eventually adapt at idle.

[twoqu]

Are we talking stock?
Think I remember that to run ABY injectors on 3B needed some SW adjustment so perhaps there would be an issue using 3B injectors even with 4 bar fpr. Obviously if you have the matching injectors to the SW then ignore!

[Error404]

What software are you running now on the ABY pin swap mate?

[Ryss]

Andy P .. excellent link. Thanks

[K Simmonds]

Just for reference I ran my 3B with it's RS2 hybrid on RS2 injectors with the stock 3 bar 3B fuel pressure reg and software with no issues. I only did it to check the injectors worked but the AFR's were better on boost as well being spot on 14.7 when cruising so I left it like it.

I'm not saying that's a good set up, far from it, just that the stock 3B ECU seemed quite happy with RS2 injectors which I'm guessing are closer in design to ABY item's than 3B.

[newsh]

I think the RS2 injectors are closer to 3B that to ABY. The 3B runs bigger injectors and lower fuel pressure than the ABY. In any case I've been running Deka 630s and a 7A FPR on an MRC map.

This SW is by PRJ. I gave him my spec (GT3071, Wagner manis, rods etc). He specified the injectors, they're 750cc EV14s.

[K Simmonds]

Ah, forgot you've moved onto EV14's, that info is completely useless then, sorry.

[Tonks4x4]

Are you still running Motronic?
I suggest the only way to get it running to 100% efficiency is to have it live mapped.
Whether it be on Motronic or finally bite the bullet and move to an aftermarket ECU giving you endless ability to play around with settings.

I can't praise Vems enough now I have been running it 6 months.

I fear that when you get to winter you will have more idle issues if you have issues now

[newsh]

Absolutely agree and the idea was to get it running on these chips then live map it properly, not sure when Dmitri will make it over here next though..

[UrS4boy]

Link to the live 20Vturbo Engine Bay Device Map

Andy P .. excellent link. Thanks

Because I am such a poor teacher, I put that info together so others can understand the issues with things like the fuel pressure regulator.

Lots more where that came from if you click on this link, bookmark it for future reference and then open any of the links to the info by clicking on the appropriate label.

http://members.shaw.ca/speedtek/UrS%20Engine%20Bay%20Device%20Map.html