M30 swapped....Almost

[SpeicherBimmer]

Ok, so I finally got around to installing my M30 ( Euro M30B34, 218hp) into my E30 (320i 1987) last week and surprisingly it went fairly well. I'd love to tell you how much I love driving the car except I haven't gotten it to start yet. I'm down to trying to figure out the thing I hate most about cars; wiring. When I bought the engine it already came with a modified M30B34 ( '85 535i) harness. I have most of the stuff hooked up, but I cannot figure out how to finish it up. The C101 connector is done, but I am having issues with the alternator/starter wiring ( is there a wire that goes form the alt to the starter or not?). I also can't figure out where the two wires coming off of the transmission housing need to plug in to. I have tried searching for pics or info on the M30B34 wiring set up on here but haven't been able to succesfully sift through all the posts. I have found tons of info on B35 harnesses but little to nothing detailing a 2nd gen M30B34 into an 87 320i. I am about to pull my hair out with this swap...I have a few options.....
Option 1
Try and figure out the wiring with the harness I have now and run Motronic 1.0. I will still have to figure out the wiring for the dash board as the plugs on the narness defintiely don't come close to matching the plugs on my dash. I have no idea how to figure that out yet. I also seem to have a startingly few number of ground wires that come to the battery too.

Option2
Is there a way to make my stock M20 (87 320i, pre FL I think...) harness work? I have an M30B35 -179 ECU sitting around I could use with it. What else would I have to change? Would I still need to change the crank pulley and injectors in this method?

Option 3
Finish taking off the harness, injectors, and crank pulley and convert my M30B34 to run Motronic 1.3. I'd rather not do this yet as it would mean another 3 weeks of my E30 being down but if it will be the best option then so be it.

I hope this makes some sense. I am getting to the point of not even wanting to look at the car as I just stae at the wiring and am lost...

[CorvallisBMW]

I here you, wiring is the bain of my existence

First off, is the '87 320i Motronic 1.1 or 1.3?

The 2 wires in the bellhousing of your transmission are for the timing reference sensors. They pick up on the rotation on the flywheel. I've never owned an M1.1 car so I'm sure exactly where they plug in to, but that's what they do. As long as you use the harness that matches your engine you should be OK.

As far as the alternator/starter wiring, I can't recall off the top of my head. Sorry!

[slammin.e28]

You can convert the B34 to M1.3 fairly easily. I did it on my e28 before just swapping in a whole B35.

1.1 is similar enough to 1.3. Harness should work. I used a super eta harness for my Motronic conversion, just had to extend a few wires.

Take this with a grain of Euro salt, as I'm not 100% on the Euro cars, but for US ones it's true.

Here's the list of what you'll need:

1 M20B27 88 528e super eta wiring harness or M30B35 harness (super eta harness in image)
1 M30B35 coolant temp sensor
1 M20B27 super eta temp sender
2 M30B35 thermostat housing plugs
1 M30B35 set of ignition wires with inductive pickup
1 M30B35 179 ECU
1.M30B35 harmonic balancer
1 M30B35 crank trigger bracket
1 M30B35 crank trigger bracket hardware set
1 M30B35 crank trigger sensor
1 M30B35 purge valve
1 M30B35 purge valve retainer
1 M30B35 purge valve retainer bracket
1 M30B35 oil level sensor (if using M30B35 harness)

You need to extend the air flow meter (4), idle control valve (3), throttle position switch (3), and oil pressure switch (1) wires to fit your M30 engine. If you choose to use the factory starter, you just need to cut off the starter switch ring terminal on the super eta harness and put on a female spade terminal.
Oil pressure switch wire is pre cut for your convenience with the rest of the harness intact.
You will need to purchase a BOSCH oxygen sensor new to complete the kit.
You will also need to purchase vacuum line to route to the purge valve, you do not have to use the purge valve however.

[RickSloan]

you can just eliminate the 2 bell housing sensors. Since you are running the B35 harness you should be using a CPS. There are no plugs on the B35 harness for those bellhousing sensors because it doesn't use them.

Yes there is wires between the alternator and starter. If i remember correctly it is actually a separate small harness that plugs into a round plug behind the alternator.

When you get that thing going you are going to have one hell of a car. That will pull like a freight train.

Best of luck!

Edit... I wrote all that thinking you were using b35 stuff... honestly you should just forget the b34 harness and install a B35 one with a B35 ecu. You will not regret it I promise and its easier to wire...

[SpeicherBimmer]

Thanks for the responses everyone...My 320i is Motronic 1.1.The more I think about it I might just have to suck it up and convert to the Motronic 1.3. I'm not looking forward to having to pull that crank pulley off that E34 535i but I guess I'll have to. Are there any special tricks I should know about mounting the new crank pulley or is it a simple bolt on affair? Also, and this might be a stupid question, but will running the ECU meant for a B35 mean I will be making the power of the B35? I know the Euro dirty B34s made about 218hp vs the 211 hp of the B35. I am not worried about the slight hp difference, more like the differences in compression ratios and fuel flow rates. I will also have to find a way to mount an O2 sensor in now as well...Guess the car will just have to be down for another 2 weeks.

Slammin- Are the other temp sensors really required?

[CorvallisBMW]

Euro motors all have higher compression, so if the b34 made more power than the b35 I'm sure it was more about the internals of the motor than the engine management. M1.3 is a superior system without a doubt, so I imagine you'll be making b34 power plus a bit more perhaps.

[SpeicherBimmer]

I just had another thought....will I have to change up to the newer style B35 starter/alternator? While looking around at the junkyard I noticed they seem to have fewer wires/connections....

[wildstoats]

Seems kind of drastic to jump right to a M1.3 conversion. What are you having problems with specifically? I did a US spec b34 into a 91 318 and would be glad to answer specific questions or take pictures of my setup. Just let me know.

[SpeicherBimmer]

wildstoats-I could really use the help. I do want to do the 1.3 upgrade, but I'd rather take my time with it. I really need to know how the start/alternator wiring is set up. I have one power wire from the batt going to the starter, the engine harness wire going to the starter, and the small black/yellow wire plugged into the top blade of the starter. On that same branch there are two small wires that I have no idea where they are supposed to go. There is also a very small, what I think is a ground wire going from the alternator to I don't know where. I also don't know where I am supposed to plug the two transmission sensor wires....As you can tell I am quite lost, and I haven't even begun to try and figure out how the dash is supposed to interface with the wiring harness. If you could send me pics of how your wiring is set up in those areas I would be EXTREMELY grateful....

[wildstoats]

Sure thing, I will shoot you some notes / pictures when I get home from work.

[SpeicherBimmer]

That would be great...I will be asleep by then as it is already almost 1 AM here in Germany...Thanks very much in advance for any help you can give me...It is extremely frustrating to be so close to being done and just hit a wall like this...

[Doughnut]

Shoot up some photo's of the boat anchor in the bay?

[SpeicherBimmer]

I'm going to try and get some pics of my wiring woes today if it stops raining, but here are a couple of the swap in progress....


I'm wearing the green shirt...

[yert315]

those headers are tasty.

Are you from the states?


What was modified on the harness you are running?

[RickSloan]

holy headers! are they custom? I think that is one of the only downside to the m30 swap is the lack of headers available. Any that are made for the m30 do not fit properly in the e30 chassis...