M30b35 swap into 1990 vert *NOW WITH LIFE!!*

[Mr. Burns]

yessiree Mr. Burns in the flesh!

anyone confirm that a m20b25 wire harness is the exact same as a m20b25 harness from an IX chasis?

[ThatOneEuroE30]

Lol so that was you jeff's post. Looks like you got a party haha

[Mr. Burns]

I've got a lead on a m20 harness. From my research fits nicer than b35 and with only marginal mods (lengthen 2 wires)

Plus...this happened all female plugs
E30 life

[ThatOneEuroE30]

I'm thinking I may find a M20b25 wire harness and start fresh.

the M30b35 auto harness is a bit nightmareish.

I'd just find the correct b35 harness. If you change your harness. Will look cleaner and no extending wires.

[Mr. Burns]

I'm thinking I may find a M20b25 wire harness and start fresh.
the M30b35 auto harness is a bit nightmareish.

[Mr. Burns]

What I can confirm is the PO of this engine had a auto to 5spd swap and the necessary measures where put into place in order that the ecu/wire harness was to recognize it as a manual transmission car. (There's a 12v constant jump that needed to be done, this was done previously)

The abundance of C101 plugs is disconcerting, as with a few "extra" wires/plugs that are complicating this.
I don't have the option of getting a m20 b25 harness or m30 b35 unless one pops up in the pnp...and that's rare
I gotta work with what I have

[george graves]

I don't know - I not so sure you can crank and fire a m30 ecu if it thinks it's a auto in a gear(Maybe you can if it thinks its in park or neutral). I know we had endless problems with(an auto engine harness) that until we said "f-this" and used my old m20(5-speed) harness on the motor. With that said, we also had a bad crank position sensor - so I can't confirm that.

[Mr. Burns]

Thank you.
In that case, can I get rid of the 3 relays on the opposite side of the engine? I'm not even certain as to where it's plugged in...fuse box?

[glnr13]

m30 only needs the fuel pump relay and the main relay to run.
the covered c101 plug is for "diagnostics", one of the other uncovered ones go to your harness connector but I don't know why there are 2 though. my m30b35 from a 735i only had 2.
ignition coil i used was the m30 one. you could use the m20 one, there are 2 posts on that as well.

[Mr. Burns]

Oy....I'm getting some pretty conflicting info upon more research.

Re: plugs at harness. None used?? Even the brown wired oNE?

I'm legit stumped on the C101 plugs....

[Mr. Burns]

Hey all, more progress and I'm stuck a little bit

I'm using a m30b35 that was originally from an automatic car.
It was later swapped to 5spd, however the automatic wire "ecu" bung is still on the harness. All necessary measures where made to have this harness work on a 5spd swap.

I've connected the proper ecu bung to my ecu. There are 3 plugs that are left behind, AND a couple of relays on a rack.
These are not indicated in my swap guide. Any ideas?



Also.
What's with the 3 C101 plugs?
Which ones plugs into the plug next to my fuse box?


Lastly (for today)
Which ignition coil to use?
My guide says to use the e30 one, however the one attached to the wire harness has two wires branched off of it


Thanks fellas
Lesson learned....label everything!!!!

[scoobydo]

Yes you will be fine thought the pulley was missing so there will be room at front. I have a spal between my rad and the intercooler, it is the low profile SPAL, couldnt source it in the UK had to get it from Poland. Isnt as powerful as what was in there factory (remember mine is a 333i) but think it will be adequate.

IC on right of this pic and radiator on the left with SPAL sandwiched

[Mr. Burns]

The clearance will change when the transmission mount is put on. Still looks like a lot of clearance. Have you got your aircon pulley still attached on the crank? Will be interested in clearance of the radiator.

Here is a picture of mine with the aircon pulley still attached (plan on still running AC). My radiator can go more towards the front of the car as currently I have it spaced out on washers so can get a bit more clearance if needed but wanted to keep the distance as far as I could to keep the max distance between my front mount and radiator.

you're right.
I will lose minimal space once I have the rear tranny brace bolted up (just waiting on bushings)

as for the aircon, I have removed the pulley and all associations with it.
I have a feeling I'll have plenty of room with my E28 rad and Spal fan. I'll be test fitting this weekend, I'll post up some pictures.

[scoobydo]

The clearance will change when the transmission mount is put on. Still looks like a lot of clearance. Have you got your aircon pulley still attached on the crank? Will be interested in clearance of the radiator.

Here is a picture of mine with the aircon pulley still attached (plan on still running AC). My radiator can go more towards the front of the car as currently I have it spaced out on washers so can get a bit more clearance if needed but wanted to keep the distance as far as I could to keep the max distance between my front mount and radiator.

[Doughnut]

Wow you have a lot of room behind your head! Have you test fitted the radiator yet?

Looks good, keep up the great work!