M30b35 swap: just a few questions.

[e30addict]

Finally got around to getting the tachometer working. Big thanks to Jean for the awesome info in his thread. Never would I have had the time to track that down. You're awesome man.

For anyone else interested, Pin 9 on c101 on the m30b35 engine harness from an e32 is a small black wire. On the 1987 325is pin 9 is blank.

On the c103 in the 1987 325is there is a similar small black wire to the one on the m30b35 engine harness. Simply run a wire to connect the black wire in pin 9 on the engine side c101 to the black wire in the c103 and you have a working tachometer.

On a side note, if you decide to do this swap, go as far out of the way as you have to to get an m5 flywheel or lighter. This thing gets to 6000 rpm in a hurry and it's fricken awesome!

[e30addict]

Awesome. Thanks again dude.

[chadthestampede]

It's the brown one. Brown one controls the gauge. The other one that sends a signal to the ecu should be blue.

[e30addict]

For the coolant sensor installed on the engine, please use the M20 sensor. You can either remove it from your M20 engine or buy a new one. For compatibility reasons, the M20 temperature sender must be used.

Got this out of Frank's thread. Does anyone know what the part number for this sensor is?

I got on pelican and it has this sensor listed as "water temperature sensor"
13-62-1-357-414-M14

http://www.pelicanparts.com/cgi-bin/...2D%39%31%29%20

They also have this one listed as "temperature sending unit."

12-62-1-710-512-M323

http://www.pelicanparts.com/cgi-bin/...2D%39%31%29%20


I'm thinking that this is the reason that my temperature guage won't work. I just need to know which of these to order. I read somewhere that the one with the brown top (the second one I listed) is the part that I need, but I was hoping that someone on here could confirm this or let me know specifically which temp sensor I need.

[Jean]

Search for my old thread, it's all in there as well as in Franks guide.

[e30addict]

Facelift wiring mods (these apply to those with a facelift shell) - the engine will run without doing them, but for everything to function correctly, the following are needed;

To get the 'economy swingometer thingy' working you need to swap pins in the M30 loom:
Pin 3 (black and white) and pin 8 (black and purple).

To get the electric windows and sunroof to work with the doors shut and for the heater blower to work at all you need to connect the black and green wire from pin 15 on the E30 C101 to a small spade connector on the starter motor.
rev counter?

Prefacelift mods (these apply to those with a pre-facelift shell);details
C104/C101 rev-counter & econometer mods

Now I'm confused. I don't mean to be a dumb ass, but I have no idea what the last bit of your post means. I'm working on a 1987 325is. It's pre-face lift, so could you clarify what c104/c101 rev-counter & econometer means.

IIRC the large diameter green wire on c103 is what you are after. been a long long time though since I traveled down that road... f&*king c101/c103 early chassis harness BS.

So I connect the green wire from the c103 to the wire from pin 9 on the engine side c101 to get the tach to work?

Thanks for the help so far, I know it must be annoying to have to try and hold my hand through this, but I'm more than a little clueless here.

[Lee Harvey]

IIRC the large diameter green wire on c103 is what you are after. been a long long time though since I traveled down that road... f&*king c101/c103 early chassis harness BS.

[rav320uk]

Facelift wiring mods (these apply to those with a facelift shell) - the engine will run without doing them, but for everything to function correctly, the following are needed;

To get the 'economy swingometer thingy' working you need to swap pins in the M30 loom:
Pin 3 (black and white) and pin 8 (black and purple).

To get the electric windows and sunroof to work with the doors shut and for the heater blower to work at all you need to connect the black and green wire from pin 15 on the E30 C101 to a small spade connector on the starter motor.
rev counter?

Prefacelift mods (these apply to those with a pre-facelift shell);details
C104/C101 rev-counter & econometer mods

[chadthestampede]

Why are you looking for that, I didn't go near that for my M30 conversion

Neither did I, but IIRC certain people had to run a wire from there to get the tach working.

[rav320uk]

c103 is in the glovebox by the ecu. I believe it's a 3 pin connector.

Why are you looking for that, I didn't go near that for my M30 conversion

[chadthestampede]

c103 is in the glovebox by the ecu. I believe it's a 3 pin connector.

[e30addict]

Thanks for the info rav and chad. I'm still a little lost, but it's a good start and excellent information. Now for my dumb question of the day. Where do I find the c103 connector?

What temp sensor are you using? When I did my B34 swap I had to use the M42's temp sensor.

I'm using the sensor that came on the engine from the '88 735i. Since I'm using the engine harness from th 7 as well I figured it would be fine. Been wrong plenty of times before though.

[wildstoats]

I used the engine harness from the 1988 735i and plugged the c101 straight to the chassis side c101 the e30. Car started and runs, no problem. The problem that I am running into is that my tach and temp gauges don't work.

What temp sensor are you using? When I did my B34 swap I had to use the M42's temp sensor.

[rav320uk]

Read this, I posted the wiring side of things for the guages on another M30 thread.

http://www.r3vlimited.com/board/showthread.php?t=183442

Rav

[chadthestampede]

Yeah. I just pluged it in and it it started right up. I was amazed myself. The problems I ran into were money, and actually putting that big bastard in the car with the trans bolted to it. I invented new swear words when we did that.

Pretty much exactly what happened to me. Amazing how much time things take with college and a job. And no money.


This will help with the wiring:

http://www.armchair.mb.ca/~dave/BMW/

From what I remember you need to splice in a wire from the e30 c103 plug into the c101 (or x20 as I think the 7 series ETM refers to it as)