MOT fail emissions

rjes · Posted: Thu Jan 21, 2010 12:16 pm Post subject:

Hello Brian,
I just read your post in which you said that you'd found an AA190 MAF, and it seems to have lowered the CO emissions. I missed that bit yesterday. I thought you'd always had some doubt about whether your MAF was the right part, but I think I was maybe getting confused. Was it the fuel pressure regulator which at some point you knew you had the wrong one?
I assume it's got rid of code 49 too then? If so, that's excellent news. Problem solved, although The MOT emissions test will prove it for definite I suppose. You did find another one for Silverbullet did you?
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

rjes · Posted: Thu Jan 21, 2010 10:57 pm Post subject:

The Beetle which has the 22680 AA190 MAF and no error code 49 has all 5 pins of the MAF used, as follows:

1 Red
2 Black
3 Black/Red
4 White
5 Blue

Hope this helps someone.......
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

syncroparge · Posted: Fri Jan 22, 2010 5:08 pm Post subject:

Yes Richard code 49 has gone. Like I aid earlier would it be possible to swap the ecu and keep the 160 green lable MAF would the wiring be the same at the ECU plugs. Just thinking for the future if my MAF dies I doubt I would be able to find another. Thanks... Brian

syncroparge · Posted: Fri Jan 22, 2010 5:09 pm Post subject:

Yes Richard code 49 has gone. Like I aid earlier would it be possible to swap the ecu and keep the 160 green lable MAF would the wiring be the same at the ECU plugs. Just thinking for the future if my MAF dies I doubt I would be able to find another. Thanks... Brian

rjes · Posted: Sat Jan 23, 2010 7:19 pm Post subject:

I'm not sure about swapping the ECU on the harness you have without spending a while looking at wiring diagrams. I'm sure it could be done, it's just a matter of checking whether any pins need swapping around in the ECU connectors.

Is your MAF wored like the one on the Beetle I listed above? I guess it must be if error code 49 has gone.
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

syncroparge · Posted: Sun Jan 24, 2010 6:38 am Post subject:

Yes Richard its wired the same
1 red 12 v+
2 black ecu -ve
3 black red body -ve
4 white signal wire
5 blue 5v+
Thanks.....Brian
P.S. I've read on legacy central that sometimes to change ecu's you might need to change injectors, but this might be for turbo engines only...

syncroparge · Posted: Thu Jan 28, 2010 10:48 am Post subject:

Just to let you know passed the mot today,
emissions CO 0.19% HC 213 PPM
Last mot CO 9.75% HC 458 PPM. So after all this time it was down to the wrong MAF fitted to the donor car. Well we live and learn.
Thanks for all the help......Brian

silverbullet · Initiate Jedi Joined: 03 Sep 2009 Posts: 25

syncroparge · Posted: Thu Jan 28, 2010 1:19 pm Post subject:

I didn't try altering the wiring when I found the 190 I fitted it and everything is great. I've been asking Subaru if they have any tech info on the wiring mod but all I get is "it's too old we have no records". You could try sourcing one from the leads I have put on the wanted ad or try pestering Subaru at your end of the country re the wiring mod. Subaru do not list a 190 as avaible just the 160. You could try another ECU that will work with a 160 MAF there has got to be a similar ECU where the pins would match up....Brian P.S. If you find anything out keep us posted.

rjes · Posted: Thu Jan 28, 2010 1:41 pm Post subject:

Syncroparge - Glad you got the MOT. A slight improvment in emissions! Whenever we last met at a show I think we discussed the problem almost certainly being due to something silly.

I think your MOT emissions test results prove my theory that the AA160 and AA190 MAF's must be calibrated very differently to justify Subaru adding wiring and a specific error code to tell you you have the wrong one.

Silverbullet - I don't see how hacking the wiring is going to help. It'd be interesting to try, but my guess is that it will have no effect on emissions, and will probably just get rid of code 49. If your MAF wire colours are the same as listed above, you have the same harness as the Beetle I looked at and Brian, so I'm 95% sure your solution would also be an AA160 MAF. There's no doubt that they are rarer than the AA190 type, but they can't be that hard to find. Have you phoned all the specialist Subaru breakers?
This German eBay shop has them new:http://cgi.ebay.at/Luftmassenmesser-Subaru-Legacy-22680-AA190_W0QQitemZ260528714289QQcmdZViewItemQQptZAutoteile_Zubeh%C3%B6r?hash=item3ca8b8b231
...not cheap though.

I would expect swapping certain ECU's to also require swapping injectors. This is one of the reasons why your best bet is to use all the negne management components from one donor car. If you swap an ECU which is mapped for low flow rate injectors for one which is mapped for high flow ones, but keep the low flow injectors, the mixture would be too lean because the injector on pulse width would be shorter.
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

silverbullet · Initiate Jedi Joined: 03 Sep 2009 Posts: 25

Well it's been a very long time coming but after a chance conversation at club80-90 I have finally aquired an AA190 "brown label" MAF!
Another member had one incorrectly installed in his 2.2 conversion and an AA160 Green label put it right, so we did a straight swap.
The crucial distinction is that it has a trimmer pot next to the 5-pin socket, where all later variants have a blind boss.
I'll have to go back to my pdf 1st gen. Legacy manual to see what it's for, but now I'm a lot more hopeful that it will come good as all the indicators are that this is the correct one to go with this early "integral lamp" ecu and loom.
I'll report back once installed and check those wiring colours while I'm at it. If all's good I'll be tracking down a spare, but it could take a while...

silverbullet · Initiate Jedi Joined: 03 Sep 2009 Posts: 25

Well it runs ok and the code 49 has gone! It's been replaced by a code 35 but that's purge valve so can be ignored for now.
The idle still creeps up to nearer 1000rpm when up to temperature, compared to 850 when cold and also has a tendancy to backfire when blipping the throttle when cold

Unfortunately my pdf manual is for 1992 Legacy and doesn't cover the brown mabel maf so it must be earlier...just what is the trimmer pot for?
Anyway I'm a lot happier. Maybe it needs to be driven round the block for the ecu to get some fresh load values with the new MAF?