M20 into 91 318is

[r3vde30]

Ok I have complete M20 B25 with harness from 90 325i, g260,driveshaft, and 4.10lsd

Car the above is going into is 91 318is.Engine/tranny removed already.My questions are as follows.

• 325i Harness seems plug and play with connector on firewall- anything special I need to do here?
• Im going to use the 325i g260/driveshaft/ 4.10 LSD- do I use the 325i CV axles or the 318is CV axles?

Anything else Im missing? Hate downtime and rather tackle this all at once.

[dashboardmonkey]

you will need a 6 cyl coding plug for the cluster if you want your tach to be accurate

[StereoInstaller1]

Got the transmission brace for the 260?

[Dyno4mance]

Shifter linkage needs to be sourced from a 325is as the one on the 318is will be too short
I have not heard of anyone doing this swap that has managed to retain a working ABS system...
axle flanges will work with both small case diff and medium size diff case...

[ZM Blue Devil]

Radiator... You keeping the m42 radiator or putting in a m20 radiator? If keeping the m42 you will need a few new pieces to make it work.

[r3vde30]

Got the transmission brace for the 260?

Yes i have the 260 brace

Shifter linkage needs to be sourced from a 325is as the one on the 318is will be too short
I have not heard of anyone doing this swap that has managed to retain a working ABS system...
axle flanges will work with both small case diff and medium size diff case...

Ok keeping the g260 shifter stuff ---- do you have more details on what or why the abs wont work?

Radiator... You keeping the m42 radiator or putting in a m20 radiator? If keeping the m42 you will need a few new pieces to make it work.

The m42 stuff is in the cars truck including radiator- Ill prob use the M20 one since I know how that one is setup

[FredK]

With a 1990 325i harness, your ABS will work fine.

The issue is in airbag cars, the ABS is powered through the bulkhead connector, the C101, at pin 20.

The transmission brace in the 318is is IDENTICAL to the transmission brace for a manual M20. The studs that mount into the body merely need to be slid out and installed in the rear channels.

The 318is CV axles are IDENTICAL to the 325i/s CV axles.

[Dyno4mance]

With a 1990 325i harness, your ABS will work fine.

The issue is in airbag cars, the ABS is powered through the bulkhead connector, the C101, at pin 20.

The transmission brace in the 318is is IDENTICAL to the transmission brace for a manual M20. The studs that mount into the body merely need to be slid out and installed in the rear channels.

The 318is CV axles are IDENTICAL to the 325i/s CV axles.

I am assuming being a 91 318is it would have an airbag??
Could you elaborate what changes need to be made to C101 at pin 20 so the abs works
Are you saying the abs does not work if the airbag is removed?
Thanks in advnce and sorry for the threadjack...

[FredK]

I am assuming being a 91 318is it would have an airbag??
Could you elaborate what changes need to be made to C101 at pin 20 so the abs works
Are you saying the abs does not work if the airbag is removed?
Thanks in advnce and sorry for the threadjack...

The ABS will work fine even if the airbag is removed.

The electrical system in airbag cars was changed a little bit, and is merely a way to identify it physically.

In a 318is, you would have to run a switched power from the main relay (terminal 87) to pin 20. Verify that on the chassis side, the wire at pin 20 is RD/YL, then use a wire tap to connect switched power to it. That's probably the easiest way to do it.

[BrewCity11]

Bumping this because i'm doing an m20 swap into a 91 318is

I'm going over the wiring and i think i'm good. The engine harness i'm using is from a 91 airbag 325i. Both the chassis and engine harness have the red/yel wire at pin 20 so i assume its just plug and play and i won't need to do anything.

I'll report back with outcome.