Motronic 1.3 with E12 intake

Blaise · Post by **Blaise** » Tue Nov 15, 2011 6:09 pm

I am just now starting the wiring of my new M30B35 and Motronic 1.3.

At this point, I have the donor harness (from 1990 735i-E32) laid across the motor and I am going to get the following parts installed:

1. E32 coil-Just need to make a bracket to adapt it to the existing fender mount
2. Idle control valve-Looks like some plumb it between the throttle body and the now defunct cold start valve vacuum port, putting the idle control valve below the intake runners.
3. Main relay and fuel pump relay-The E32 harness has these near the ECU bracket, while our E12's located them on the left fender.

From what I gather, this conversion has not been too common on our cars. If you have done it before, I would love your input. If not, I hope to share what I learn.

Cheers,

Blaise

BTW, I just finished my euro bumper installation....looks great.

anthony · Post by **anthony** » Wed Nov 16, 2011 1:48 am

I used the engine harness from a 1988 528e it is plug and play. The 528e battery is same location as the e12. However, I still had to shorten and lengthen some wires. Plus, groups wires do not exit at the correct location. The idle control valve is at a different location on the 528e. It works but does not look aesthetically pleasing.

The best would be to remove the wire sheathing and combine the best of both the 528e and m30b35.

Your project is much more extensive than mine. I swapped the entire engine so no modifying- just adjusting lengths.

Making a harness specific for my car from the ECU to the battery and everything in between is my ultimate goal.

labimmer · Post by **labimmer** » Wed Nov 16, 2011 10:41 am

Are you putting a M30B34 or B35?
I swapped the original engine from M30B30 to M30B32 and it was easy.
Since my 530 is from 1975 I had to use original bores. There was not enough clearance from brake buster.
The donor engine came from 82 733i with the 5 speed 265 tranny. On 11/16/11, anthony <ketcham99@comcast.net> wrote:

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I used the engine harness from a 1988 528e it is plug and play. The 528e battery is same location as the e12. However, I still had to shorten and lengthen some wires. Plus, groups wires do not exit at the correct location. The idle control valve is at a different location on the 528e. It works but does not look aesthetically pleasing.The best would be to remove the wire sheathing and combine the best of both the 528e and m30b35. Your project is much more extensive than mine. I swapped the entire engine so no modifying- just adjusting lengths.Making a harness specific for my car from the ECU to the battery and everything in between is my ultimate goal.
Anthony1980 528i 3.5 motronic 1.3
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anthony · Post by **anthony** » Wed Nov 16, 2011 11:41 am

I am installing a m30b35. I big part of that is installing motronic 1.3.
Motronic uses a 55 pin connecter at the EUC. A wire harness from a 88 528e has that as well as all other connections, plus the battery leads are the same location as the e12.

I have installed 1.3 on my m30b34 in preparation of the engine swap. A couple of weeks ago I installed the intake manifold so all ports are accounted for. This is important because the car needs to be smogged. The first thing inspectors do is check for emissions so every port and vacuum tube needs to be accounted for, no bolts in the end of a vacuum tube.

There are no loose ends but I have the distisbutor leads execting at the coolant and engine temperature location and going across to the the original e12 bracket. On the b34 harness they came straight down exciting near the the fire wall.

Blaise, on the other hand is keeping the original e12 intake manifold and runners and this requires more mods.

I wanted to swap wires, but it requires taking the harness completely apart and reinstalling the leads into the 55 pin connector. I think to make a great looking fit, one would have to start from scratch.

Blaise · Post by **Blaise** » Wed Nov 16, 2011 1:08 pm

Here is the installation of the Idle Control Valve. I figured that it just has to go from the pre-throttle body air port, to any post-throttle body port.

I went from the stock throttle body location to the cold start valve intake port, locating the idle control valve under intake runner #4. Motronic 1.3 does not use the cold start valve. Most examples that I have seen of this swap install a small plate where the cold start valve goes.

It does clear the coolant hose going to the reservoir.

Since the idle control valve is controlled by the new ECU, it is my understanding that it replaces both the stock E12 and the A/C idle valve. If the idle drops, due to A/C or cold engine or anything else, the computer compensates. On the stock unit, it closed with heat only. The A/C valve opened when the A/C was turned on. Take all of this with a grain of salt, as I am just learning.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/x ... site"><img src="https://lh6.googleusercontent.com/--vuU ... _00112.jpg" height="400" width="299"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/k ... site"><img src="https://lh5.googleusercontent.com/-NsOz ... _00113.jpg" height="400" width="299"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/X ... site"><img src="https://lh5.googleusercontent.com/-4lF6 ... _00114.jpg" height="400" width="299"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

In regards to Anthony's comment about the 528e battery location being the same as the E12, I don't really understand how this matters. On the E32 harness, the only item that really differs in location is the main and fuel pump relays. They are located close to the ECU plug. They will simply need a hot fused wire, which can be routed as you see fit. Since it is switched (11-22-11-I was wrong about this, it comes from the battery directly), it does not originate from the battery. Am I missing something here?

Anthony, where did you pick up the power (red fused wire) for your new harness? I was thinking of using the heavy gauge stock red wire that used to go to the combo relay cluster (have to check what it was connected to).

I have the whole harness pulled apart (as seen in photos) and will extend and move things as I see fit. It is a little intimidating, but I figure that it will come together if I take it one step at a time.

My thought is to button up and wrap the ends that are already correct. For example, fuel injectors, coolant temp sensors, etc... Then start to loosely bundle the harness with masking tape to get the distances and routing right.

Anyway, more soon.

anthony · Post by **anthony** » Wed Nov 16, 2011 4:04 pm

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!

Blaise · Post by **Blaise** » Thu Nov 17, 2011 3:04 pm

I installed the E32 coil.

I needed to make an adapter bracket to mate it to the E12 fender.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/a ... site"><img src="https://lh3.googleusercontent.com/-sVIK ... G_2500.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>

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/s ... site"><img src="https://lh6.googleusercontent.com/-llY5 ... G_2506.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>

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/s ... site"><img src="https://lh3.googleusercontent.com/-R6y9 ... G_2508.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>

Blaise · Post by **Blaise** » Thu Nov 17, 2011 3:20 pm

I figured that I would start by buttoning up the ends that I know are correct.

The E32 fuel injector plugs were part of a big plastic tray that sat on top of the injectors. For this reason, they are without insulation or the rubber boot.

I have a local supplier that sells the boots, plug housings, connectors and de-pinning tools.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/d ... site"><img src="https://lh4.googleusercontent.com/-IFqh ... G_2544.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 tried to take the plugs apart, but it was really a bare. So, I figured that since I had many to do, I would figure out how they really worked.

I cut one in half.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/N ... site"><img src="https://lh4.googleusercontent.com/-OQ_y ... G_2529.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>

The connector has barbs on BOTH sides.

Now, take a look at the factory plug housing.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/7 ... site"><img src="https://lh6.googleusercontent.com/-KwHW ... G_2547.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>

See the crimp marks where the rubber boot would sit? It looks like BMW crimped the plug here, using heat. It basically creates an internal stop for the barb on the other side of the connector. The problem is that the de-pinning tool does not reach this barb.

If you try to pull these apart, you have a high chance of damaging the wire connection.

I opted to cut the old housing off, keeping the connectors intact, and then installing a new housing.

alotawatts · Post by **alotawatts** » Fri Nov 18, 2011 11:00 pm

Blaise wrote:
<table><tr><td><a href="https://picasaweb.google.com/lh/photo/X ... site"><img src="https://lh5.googleusercontent.com/-4lF6 ... _00114.jpg" height="400" width="299"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>

Nice work !

Where did you buy the ATE Brake booster ... or did you refurbish the old one ?

Blaise · Post by **Blaise** » Sat Nov 19, 2011 11:27 am

alotawatts wrote:
Where did you buy the ATE Brake booster ... or did you refurbish the old one ?

I just refurbished the best one that I had

Blaise · Post by **Blaise** » Sat Nov 19, 2011 11:45 pm

I am now working on identifying the wires that connect to the E12 fuse box. I think I have them, but I am tracing the unused wires, to make sure that they are in fact unused.

I remember finding a diagram of the motronic 55 pin ecu connector, with labels for each pin, but cannot seem to find it. Anyone have an idea of where I can find it online.

Thank you,

Blaise

anthony · Post by **anthony** » Mon Nov 21, 2011 1:39 am

It is in the Bentley and

http://diyefi.co.uk/Motronic_55_Pin_Wir ... g_templete

Blaise · Post by **Blaise** » Mon Nov 21, 2011 3:28 am

Thank you Anthony. That was not the one that I remembered, but quite helpful.

My issue is that I do not recall which of the wiring harness plugs goes to the Crank Position Sensor and which goes to the Spark Plug Wire sensor. They look identical and I am unsure about which is which. I see in the diagram that you posted that there is a pin for CPS, so I should be able to locate it with my ohmeter. Let me know if you know another way to ID them.

Otherwise, things are going well...so far. Just made a bracket for those.

Blaise · Post by **Blaise** » Mon Nov 21, 2011 4:47 pm

Anthony,

Thanks for all the help and responses.

The link that you posted for the ECU plug, had a PDF download, which gives me just what I need. It shows a wiring diagram of the harness.

I have a few questions for you.

CHECK ENGINE LIGHT:

I like the idea of using it. I read that you used a 12V light, that you connected to the grey wire coming from the ECU and to the green coil wire. How does this work? I just want to make sure that I get it right. I would have figured that grey fed positive voltage when there is a fault and the other end of the bulb just needs a ground. Am I missing something?

TACHOMETER:

I have been told to run a black wire to the coil, from the existing tach wire in the E12 fuse box connector (I have a note that this is pin #5, but I also have a conflicting note that says it is not used). What did you do to run your tach?

What about the black wire in the M1.3 harness (pin #6 from the ECU)? Can that be used to drive the tach?

Cheers,

Blaise

anthony · Post by **anthony** » Mon Nov 21, 2011 10:28 pm

On the check engine light, as far as I know it's working. That is, the light goes on when the key is in run position before cranking and when cranking and goes off when the engine is running. The light has gone on when running and I followed the procedure to get the error code and turn it off. 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.

On the tach I took the black wire from the ECU#6 output engine speed. I ran it behind the dash with a separate connecter. Pin 5 on e12 fuse box is left empty

On the sensors pin 8 and 31 for cylinder identification and pin 47 and 48 for crankshaft ident. The only way to tell is to use the ohmmeter.

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