I am look for a replacement ECU (035-905-383) for my 83 Ur Quattro. Any insight on obtaining one would be greatly appreciated.

Regards, Tom Westover 949-240-6041
tomwestover@earthlink.net

whats it worth?

Email: glen <glen@proflaggers.com> Phone: 603-783-0484
Description
ur-q ECU MAC-02 Audi P/N 035 905 383F, PERFECT example.

His 85 urq is going to holland.

If sourcing a replacement ECU *really* becomes an issue..

You can always go to a MAC 11 (MC motor 5000T).

Yes, that requires a MAC11 wiring harness, and all the related bits (air temp sensor, coil, wastegate Freq valve, knock sensor(if it'll mount to the block) and probably some other bits.

And some wiring skill, of course!

But: A much newer ECU, easier to get chips for, controls timing AND fueling (to some extent)and does 'active' wastegate control and knock sensing. A good 'all round' upgrade, as it were.

(Vs the MAC 02 that only does timng contol..!)

As much more common, can probably be obtained for a reasonable amount.

Just something to think about as an alternative..


So what is wrong with the original ECU?

Right! Of course the MAC o2 has fuel control, to do the O2 correction. I never thought of it that way. (How about the Euro version that had no 02 sensor? Did they have a FV too?)


Would this be more correct then?

"MAC11 has fuel mapping, whereas MAC02 only has fuel correction for O2 sensor"

(WX fuel enrichment is done via hoses and solenoids, throttle switches and uses the Control Pressure Regulator)

I think my husband Craig emailed you? We're just doing car stuff this weekend if you want to pick one of ours up. Shoot us an email. Don't you have a Coupe Quattro also?

<center><img src="http://pictureposter.audiworld.com/84174/imgp2894leftfrontsmall.jpg"></center><p>I have a S. Eiche chipped Mac 02 from my former 1983 WX engine that you can have for $400, ready to go. Lots of other parts I will be offering for sale.

<center><img src="http://pictureposter.audiworld.com/84174/sppicture1croppedsmall.jpg"></center><p>and lots of other parts to be listed

Price will depend on the time spent and parts used. For a full rework I would think that at the most it will be $150. That includes new capacitors, replacement of blown transistors and drivers.

I am unable to test the MAC02 myself but there may be a local UrQ owner who may be willing to allow a test session?... anyone.. anyone...? Craig? Martin? Anyone else?

The MAC-02 on the WX DOES have basic fuel maps (for open loop operation, WOT, etc.) that control the frequency valve, just like the later MAC-xxs such as the MAC-11.

The MAC-01 used on the WR engined cars does not have any mixture control, so it has no frequency valve.