Need rebuilt brain for my '88 3.2

[Buck toenges]

Can anybody suggest where I can get a rebuilt brain or get my brain serviced for a '88 3.2

[Tim Polzin]

Buck, are you 100% certain it is the DME? Did you swap it with another to confirm?

These boxes are pretty robust, but do suffer from fatigue cracks near large components. If you are 100% certain it is the DME, pull it out, remove it from the box and look very carefully on the analogue board (the bottom one with all the transistors).

If you are certain it is the DME, this one will work when you swap out your Eprom with the BMW one.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33596&item=1876201406

This one too.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=6763&item=1876258659

The only difference I noticed was that the shift light only came on at redline, otherwise it appeared to perform exactly the same

Tim

[Thomas Owen]

Have you narrowed down your problem to the DME? If you want, I can send you one that is known good, you can try it.
Regards,

[ChrisBennet]

Hi Thomas and Tim,
It has recently come to my attention that not all "'059" BMW boxes are 28 pin. Someone who had a problem with their DME got a BMW one and discovered that it had a 24 pin EPROM. I made him a Porsche Eprom but he hasn't tried it yet. If the code on the CPU8051 is the same he should be all set. I'll let you know how the experiment works out.
-Chris

[ChrisBennet]

Buck,
Can you describe the symptoms? My "spare" 89 DME had idle stabilizer problems and I am aware of another "broken" DME with the same problem.
-Chris

[Buck toenges]

I am not getting the grey wires to the injectors to ground out when starting. The red wires and grey wires are all 12v. The grey ones are supposed to ground out so the injectors work properly. Car runs if I squirt starter fluid into throttle body but won't start on its own. Tried noids and no lights.

[ChrisBennet]

Originally posted by Buck toenges
I am not getting the grey wires to the injectors to ground out when starting. The red wires and grey wires are all 12v. The grey ones are supposed to ground out so the injectors work properly. Car runs if I squirt starter fluid into throttle body but won't start on its own. Tried noids and no lights.

Sorry Buck, I didn't make the connection to your previous post. I'm gettin' senile what can I say? If you can't find anyone closer to try swapping brains with, PM me (little button below this message) and we can work something out.
-Chris

[Harold_89_911]

Do you have the factory alarm by any chance? I had a similar problem with my 89 and was convinced it was the ECU. Posted on this board and the consensus was that the Motronic rarely fails and, if it does, you usually have different symptoms. So I had my mechanic look at it and it turned out to be burned contacts in the alarm module. The way he detected it was by measuring the voltage to the fuel pump while cranking. Was fine under static conditions but was fluctuating when there was an actual current draw. Just my experience.

[Buck toenges]

I do know that I have to put power to one of the small black wires inorder for the dme to click and start the car.

[Tim Polzin]

Hi Chris:

My experience is based on a statistical population of 1. If some of the "59" boxes have 24 pin Eproms, it also means the 8051 are using internal memory. Even the early 911 boards with 24 pin Eproms had provisions for 28 pin chips, but need to set the address lines and disable the internal 8051 memory access. Should work the same way with 24 pin "59" boards. Remember that old 911 DME where I used a 28 pin Eprom?

I can take a photo of the Eprom layout of my "59" so you could duplicate the jumpers on your friend's "59".

Cheers...Tim

[dwightp]

Buck:

I have a late model 3.2l 28 pin ECU available for sale if you decide you need one. I bought it for an upgrade project about 4 months ago, but switched to motec. So it's a paperweight at the moment.

[ChrisBennet]

Originally posted by Tim Polzin
Hi Chris:

My experience is based on a statistical population of 1. If some of the "59" boxes have 24 pin Eproms, it also means the 8051 are using internal memory. Even the early 911 boards with 24 pin Eproms had provisions for 28 pin chips, but need to set the address lines and disable the internal 8051 memory access. Should work the same way with 24 pin "59" boards. Remember that old 911 DME where I used a 28 pin Eprom?

I can take a photo of the Eprom layout of my "59" so you could duplicate the jumpers on your friend's "59".

Cheers...Tim

Tim,
Hopefully we'll find that the internal code in the 8051 is "generic 6 cylinder" and just the tables in the Eprom are different.
I have all the info to change it to 28 pin if it comes to that. I think you sent it to me before.

For those of you wonderng what we're talking about: Tim discovered a while ago that the DME's with 24pin Eproms have some of their code right on the CPU (a custom 8051) and the rest of the code is in the Eprom. He also discovered that the 28pin DME's had the internal CPU memory disabled so all the code+data was in the Eprom.
-Chris

[twin plugged targa]

Buck,
Please do find an ecu you can borrow and plug in to check for sure!.
They are simple to install/plug in.
A garage lent me one for 5 mins to discover that my ecu was fine.
The ecu's are solid/reliable, unless of course a lot of water gets on the floor of your Porsche!
Good luck
Ben

[ChrisBennet]

Hi guys,
I just got a message from the person who was trying the 24pin Porsche Eprom I made him in their 24 pin BMW box. It wouldn't start.
-Chris

[Thomas Owen]

Chris - was the box for a 4 or 6 cylinder BMW? Remember that resistor change we discovered for the 2 different configurations....You will probably have to get the 8051 ROM disabled and go with a 28 pin chip. Tim??

[ChrisBennet]

Originally posted by Thomas Owen
Chris - was the box for a 4 or 6 cylinder BMW? Remember that resistor change we discovered for the 2 different configurations....You will probably have to get the 8051 ROM disabled and go with a 28 pin chip. Tim??

I think the 059 BMW box is a 6 cylinder box. His BMW box ran in his 911 so we know the analog side is OK at least.
-Chris

[Tim Polzin]

Yup, six.

[Buck toenges]

Just connected the brain and it is good to go! The sweet sound of 6 cylinders is a beautiful Thing!
Thanks for the help guys!

[Tim Polzin]

New one or fix the old one?

Tim

[Buck toenges]

It was a rebuilt one. Now I am supposed to ship the old core back. Is there another option here with the old one?