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I am getting ready to do a motronic 1.3 swap in my '75 e12, have any of you guys done this swap before, if so is there a wiring diagram?

I am in the process of that right now. This website from mye28.com are the parts listed to convert to 1.3. mye28 has lots of wiring help, you just have to search for it.

Remember they are converting from an e28. I have already converted to motronic 1.0. There is no L-jet at all in my engine compartment. For sure you need a 1.3 ECU and a compatible engine harness and then all applicable accessories AFM ect. I used the firstfives FAQ to convert motronic wiring harness to e12 fuse box. That part looks like it will by the same for 1.3. One difference from 1.0 and L-jet is 1.3 does not have a cold start valve. So I have acquired a 1.3 air-intake manifold and gas/injector rail. Depending on what you are keeping from E12 will determine the work or fabrication you will need to do.

I hope this helps

www.mye28.com/viewtopic.php?t=63095

I m going to try to to the same thing the way i am tackle this project is use the faq e28 wiring to e12 on firstves web and the b35 faq on my e28 wich shows how to wire a e28 to e34 hope it helps

http://www.firstfives.org/faq/e28_wirin ... rsion.html

http://www.mye28.com/viewtopic.php?t=60 ... conversion

anthony wrote:I am in the process of that right now. This website from mye28.com are the parts listed to convert to 1.3. mye28 has lots of wiring help, you just have to search for it.

Remember they are converting from an e28. I have already converted to motronic 1.0. There is no L-jet at all in my engine compartment. For sure you need a 1.3 ECU and a compatible engine harness and then all applicable accessories AFM ect. I used the firstfives FAQ to convert motronic wiring harness to e12 fuse box. That part looks like it will by the same for 1.3. One difference from 1.0 and L-jet is 1.3 does not have a cold start valve. So I have acquired a 1.3 air-intake manifold and gas/injector rail. Depending on what you are keeping from E12 will determine the work or fabrication you will need to do.

I hope this helps

www.mye28.com/viewtopic.php?t=63095

My car too already has the motronic 1.0 swap done to it, all I need to know is the wiring from my fuse panel to the 1.3 pin out!

I already have everything for the swap:

- b35 intake manifold
- b35 fuel rail
- b35 crank trigger and bracket
- b35 harmonic balancer
- complete engine harness and ecu

I am going to go with the miller maf conversion as well, I just want to have all of the wiring figured out before I start!

Brent

bkbimmer wrote: My car too already has the motronic 1.0 swap done to it, all I need to know is the wiring from my fuse panel to the 1.3 pin out!


Brent

Have you figured this out yet? Just curious, as I am looking into this now.

It will run like a bat out of hell and get better gas mileage too! Around town you'll shift up quicker and therefore shift less. It's ALL GOOD!!

Even after 7 years, I can still get angry at the bitch who killed my car. Sure do miss it.

Oh yeah. Get the E34 manifolds and cat. They'll fit nicely under the E12. And you can graft it to the E12 exhaust system w/o much trouble. I think Karl was the pioneer on that if memory serves.

I am currently adapting the motronic 1.3 engine harness, from an 1988 528e, to fit on the b35 and in the e12 engine bay.

I removed all, or most, of the shielding from the harness. And moved wires to exit at the correct spot. So far I have had to shorten the AFM and air idler valve. Not a problem

But I will have to lengthen the six wires needed to reach the fuse box. The battery cables are long enough.

I guessed wrong. I thought I would only have to shorten wires.

As for the 3 relays they remain in limbo. They are located at the fuse box end.

The current, b34, harness is perfect- for a E12, but it is not fifty five pin.

The harness is going in ugly.

In the future I will consider the e34 harness, and other alternatives.

My goal now is to get it running.

anthony wrote:I am currently adapting the motronic 1.3 engine harness, from an 1988 528e, to fit on the b35 and in the e12 engine bay.

I removed all, or most, of the shielding from the harness. And moved wires to exit at the correct spot. So far I have had to shorten the AFM and air idler valve. Not a problem

But I will have to lengthen the six wires needed to reach the fuse box. The battery cables are long enough.

I guessed wrong. I thought I would only have to shorten wires.

As for the 3 relays they remain in limbo. They are located at the fuse box end.

The current, b34, harness is perfect- for a E12, but it is not fifty five pin.

The harness is going in ugly.

In the future I will consider the e34 harness, and other alternatives.

My goal now is to get it running.

Thanks for the update. I will share my own experience...when I get to the harness part.

I installed motronic 1.3 on my m30b34. (Some time ago I installed the harmonic balancer)

I wanted the engine harness to fit proper like. Most of all I wanted it to work. I'm glad I did I crossed (I think) the green and yellow that connect to the idle control valve.

I was chasing it down for a day and a half. The car was idling at 1500. I took the voltmeter and started to check every wire.

Car runs fine.

anthony wrote:I installed motronic 1.3 on my m30b34. (Some time ago I installed the harmonic balancer)

I wanted the engine harness to fit proper like. Most of all I wanted it to work. I'm glad I did I crossed (I think) the green and yellow that connect to the idle control valve.

I was chasing it down for a day and a half. The car was idling at 1500. I took the voltmeter and started to check every wire.

Car runs fine.

Can you share the sequence of wiring hookups for the fuse box connection?

Also, does your car have A/C? If so, did your compressor bracket conflict with the M1.3 crank position sensor?

On the a/c, yes, there was a conflict. I got a e28 a/c compressor some time ago in my scavenger hunting. I had a e28 bracket from the first m30b34. An ac guy is going to make the two hoses I need to complete the system.

In a post Mike W had an answer to solve this problem, there exist a bracket that is compatible with both the e12 compressor and the crank sensor. I don't remember, but it sounded rare.

From the super harness

Big green, you only need one, and they are all connected in the engine harness, goes to e12 fuse pin #4

Black yellow to e12 fuse pin #1

Blue to e12 fuse pin #3

Purple green to e12 fuse pin # 8

Brown green to e12 fuse pin #7

Brown white to e12 fuse pin #6
Empty #5 and #2

That leaves the check engine light. It is the gray wire. I pulled it from the harness and have it excit in the glove box. I got a 12 volt light with two leads, from an electronics store. I spliced the gray into one end and the other I spliced into the green ignition. It turns on during starting and then goes off after engine is started.

Here is some more of the same and pictures.

http://www.firstfives.org/bboard/viewto ... nthony[url][/url]

That's great Anthony. Thank you.

I will likely modify my e12 bracket for the compressor, as I have three:)

I have the motor assembled and mocked up on the engine stand, ready to figure out the wiring.

I noticed that the M1.3 does not have a cold start valve. Do you just run without? Are any of you using the L-jet intake?

I am using the m30b34 manifold which has a cold start valve. So the the valve is there with no wires attached.

The m30b35 manifold is not designed for a cold start valve.

Anthony:

Did you use the purge valve?

Blaise