Motronic ECU Part Numbers

[teardrop]

I have a UK 89 3.2 in which, as part of my never ending search for very intermittant no start problems, I removed my ECU/DME computer inorder to clean the contacts and reflow any bad joints.

I noted the numbers on the outside of the box which were as follows...

0 261 200 078
911.618.111.19
TYP 911 MWS-01

The eprom inside had a sticker on it with 1267355357.

Now, in browsing around tonight I found the following links

http://www.bba-reman.com/catalogue/porsche.htm
http://www.atpelectronics.demon.co.uk/Catalogue/porsche.htm
http://perso.wanadoo.fr/mtsa-atp/porsche.htm

All of the above have tables that look like they probably come from the same source (Bosch?) but in each case they show that the numbers on my ECU indicate it should be in a 85/86 not an 89.

Can anyone with a spare 10 minutes post the numbers on their 3.2 ECU boxes so I can see whether my original has been replaced with an earlier one?

I guess either mine has been switched with an old one although (the eprom is a 27C64 28pin), or, the tables are incorrect.

What is the difference between the 078 (85-86) and the 084 (86-89) anyone know?

Thanks for any help

Andy

[jwill911]

Hi Andy,

If you have the little Carrera spec book, in the ignition section (I don't have mine here). It references the ignition timing specifications as 3 degrees +/- 3 ATDC until 11/86 when there was a ECU change so after 11/86 ECU/DME part # is 911.618.111.20, and the timing should be 3 BTDC +/- 3 degrees.

Sounds like you have an earlier one. Check your timing it is probably 3 degrees ATDC.

Regards,

[teardrop]

What diffference did the change in timing have on the Carrera's.

Any idea what effect this would have on my car?

Cheers

Andy

[Tim Polzin]

There was a thread by stevew about 6 months ago dealing with the differences of the various chips.

Check It Out! OEM, Autothority, Weltmeister chip maps!

Hack and program you own Motronic Chip

There, I found them. Should have some good info.

Tim

[jwill911]

I did a little checking on this subject, prompted by my bi-annual smog inspection. Since my car is a 8/86 build date MY 87 the sticker in the engine compartment indicates an idle timing of 3 ATDC. Since my DME was changed with a newer one (referenced in earlier post) my idle timing was 3 BTDC. And I failed my inspection. I put my original stock chip back in and it made no difference at idle as compared to the Weltmeister chip. I think most of the difference would be at higher RPM. But the change in DMEs is probably more than just the chip, I would suspect. Maybe the link provided by Tim will be more imformative.

Regards,