Motronic 1.3 with E12 intake

[Peter Florance]

Blaise
What did you do for injectors?

[Blaise]

Blaise
What did you do for injectors?

Stock injectors for the M30B35

[Blaise]

I am now making a bracket to hold the new main relay, fuel pump relay and diagnostic plug form the M1.3 system. As it turns out, the old bracket that held all of this on my 1977 E12 is a good starting point.

So, I am trying to figure out if I can ditch all of the old wiring that went to the original (1977 530i with thermo reactor system) combo relay, emissions solenoids, etc...

These are the wires in question:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/L ... site"><img src="https://lh6.googleusercontent.com/-9P3m ... G_1361.JPG" height="480" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... tr></table>

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/4 ... site"><img src="https://lh5.googleusercontent.com/-TfrH ... 0008-1.jpg" height="478" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... Electrical questions</a></td></tr></table>

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/E ... site"><img src="https://lh3.googleusercontent.com/-_fug ... 0002-1.jpg" height="478" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... Electrical questions</a></td></tr></table>

I did find this great diagram, from Peter Florance, but it is for a 1981 E12, and in turn does not have the solenoids and the huge resistors.

http://www.firstfives.org/faq/ljet/528i ... ematic.PDF

This one gives me a little more info on the EGR (emissions system):



Any insight on these wires? What were those resistors for? I assume they are resistors.

[Peter Florance]

The six resistors are ballast resistors and are not needed on modern high resistance injectors.

[Blaise]

The six resistors are ballast resistors and are not needed on modern high resistance injectors.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/b ... site"><img src="https://lh5.googleusercontent.com/-8SYY ... 0003-1.jpg" height="478" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... Electrical questions</a></td></tr></table>

Thank you Peter.

One more thing out of the way. The engine compartment is certainly getting less crowded with this new motor.

[Blaise]

They exit with the battery leads. The 88 528e harness is very close motronic 1.0. So the three relays and the connector to the e12 fuse box is all right there. But it is not clean.

The E32 1.3 has heavier gauge hot and ground plus it combines the 02 sensor into the fuel relay so only two relays.

If I had the proper tools I would take my m30b34 1.0 harness de-pin the ECU connector and repine it to the 1.3 55 pin and combine what works best with the e32 harness.

But I don't have the time to do it!

I started working on locating these relays. I was wrong in my original post about the power being switched...it goes right to the battery, as you had said. It was not really hard to run them to the left side of the harness...photos soon.

[Blaise]

On the check engine light....

I think I got the green from a 528e engine schematic. I picked up the green from under the dash. There are pics in a previous post. It does sound counterintuitive. I believe I put the ohmmeter on the gray to confirm.

Anthony,

Would you be able to point me in the right direction on your pics of this (post post) and this E28 schematic? I like the idea of having this light.

Cheers,

Blaise

[anthony]

The 1988 528e engine schematic I got from a chilton automotive manual. Mine of course is coming apart and I can't find the pages but no matter. Motronic 1.3 pin 15 is engine lamp output. I looked to the 528e schematic for a clue which led to green.

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

[Blaise]

I am moving along with the harness and will post some photos soon. I am cutting and extending to make it fit the E12.

Some of the E32 wires are specialty wires. For example, the crank position sensor, the spark sensor, the coil and there is one other.

In extending most of these, I was able to grab the correct wire from a spare harness.

But for the coil, I don't have any spare special wire.

It can be seen in the photo below, towards the top. Large center core, then insulation, then foil wrap, then wires surround it and thick outer casing. I imagine there is a reason for this configuration.

The inner core runs to the coil. The outer wire is a ground. As it nears the coil, the outer just stops.

Can I extend just the center wire? I just need to add a couple feet to reach the coil.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/E ... site"><img src="https://lh6.googleusercontent.com/-o8t1 ... _00124.jpg" height="640" width="478"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... bsite">E32 BMW coil wire</a></td></tr></table>

[Blaise]

Here are a few update photos...

I am getting closer to having the engine harness ready.

I made this little wire holder to help with all of the soldering:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/S ... site"><img src="https://lh5.googleusercontent.com/-EUEF ... G_2721.JPG" height="300" width="400"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

I ended up adding well over a 100 feet of wire to the harness. The ECU plug was extended by 2 feet:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/s ... site"><img src="https://lh5.googleusercontent.com/-leyg ... G_2780.JPG" height="400" width="300"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

[Blaise]

Edit...I apologize for all the edits to this post. It started with a few questions, which I have been able to answer. So, I have posted what actually is needed here, in hopes that it will help the next person who does this conversion.

Now, I am wiring the starter, alternator and battery.

STARTER:

The starter has three connections.

1. Large lug (30) for positive lead to battery
2. Spade (50)-Black/Yellow to ignition
3. Spade (15a)-Black/Red to coil NO LONGER NEEDED

In doing a little research (http://www.unofficialbmw.com/images/bos ... arters.pdf), I found that the black/red (starter to coil) wire has a resistor in line sometimes and other times not. Chilton shows it, Haynes does not. It is my understanding that this wire was intended to supply power to the coil during starting, to ensure that one had good spark to start. But, with points ignitions, this was burning up points, so a resistor was added.

In the case of my M30B35 Motronic 1.3 conversion, I will not need this starter to coil (Black/Red) wire. It can be deleted.

ALTERNATOR:

My alternator has three connections. One large lug for the large positive battery lead and two spade connectors.

1. Large lug for positive lead to starter
2. D+ spade....Blue exciter wire to E12 fuse box
3. + spade...not used
4. Grounding wire from housing to engine case

Here is a good article on the function of the alternator:

http://www.pelicanparts.com/techarticle ... eshoot.htm

[Blaise]

I am finally done (I hope) modifying the motronic 1.3 engine harness to fit the E12. I had thought to test the car before doing a final friction tape wrap, but now realize that it would be too much work to remove the harness after the car is put together.
&#8232;So, I am wrapping away and crossing my fingers that I got it right.

It takes quite a bit of 3M friction tape to do this (10+ rolls), but despite being a bit tedious, it is satisfying to see it coming together.

Next I will permanently install the intake, headlights, grills, hood, etc...

Then focus on the dashboard side of things.

[Blaise]

For those of you who have done the M1.3 conversion, where did you locate the Crank Position Sensor and Spark Sensor plugs?

I made a bracket to mount them to the valve cover, but I don't like it. It is too exposed and looks silly. I may try to mount them below the intake log.

[Blaise]

Just an update:

I started to install the harness in the car:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/a ... site"><img src="https://lh4.googleusercontent.com/-CXtg ... G_2797.JPG" height="480" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

I had to stagger the CPS and Spark Sensor plugs to avoid the throttle control rod.

Another photo:

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/q ... site"><img src="https://lh4.googleusercontent.com/-NsCh ... G_2799.JPG" height="480" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

Switching between exhaust work and wiring.

[Blaise]

I am now making a bracket to hold the new main relay, fuel pump relay and diagnostic plug form the M1.3 system. As it turns out, the old bracket that held all of this on my 1977 E12 is a good starting point.

So, I am trying to figure out if I can ditch all of the old wiring that went to the original (1977 530i with thermo reactor system) combo relay, emissions solenoids, etc...

Any insight on these wires? What were those resistors for? I assume they are resistors.

I have completed the removal of these old wires. I hope I got it right. If not, I will have to come back to edit this post later.

In short, all of the wires could be abandoned (and insulated), or traced back to their origins and deleted (you choose), except for two.

The first is the Brown/Violet wire that goes from the fuse panel side plug (and to the new M1.3 fuel pump relay) to the old relay that was between to fuse panel and the firewall. If this wire is left alone, the new relay will NOT communicate with the fuel pump in the back of the car.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/K ... site"><img src="https://lh3.googleusercontent.com/-c9iJ ... G_2906.JPG" height="480" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

The second wire is the Green/Violet that went from the old relay to the fuel pumps in the back of the car. I did not actually put my ohmeter on this one, but instead reviewed a wire diagram.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/X ... site"><img src="https://lh4.googleusercontent.com/-jO-e ... G_2907.JPG" height="480" width="640"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

These two wires must be connected.