m20b27 to m20b25 swap

[onesloweta]

I am getting a b25 and looking to swap it into my 85 with the eta motor in it. Is it pretty much a direct swap? And should I use the eta harness or b25 harness. Ive been looking on the net and cant find anything that helps.

[E30_fiend]

I am getting a b25 and looking to swap it into my 85 with the eta motor in it. Is it pretty much a direct swap? And should I use the eta harness or b25 harness. Ive been looking on the net and cant find anything that helps.

You will need to use the b25 harness and ECU for the swap. Most everything else you can use again. The tranny and all that is compatible with the b25 motor

[onesloweta]

So the harness should fit right in the connectors on the car?

[SpecM]

So the harness should fit right in the connectors on the car?

sort of... there are some wiring issues with the body harness

[onesloweta]

so I should just splice the wire to the old connector?

[SpecM]

so I should just splice the wire to the old connector?

search... it is a well-documented swap

[onesloweta]

search... it is a well-documented swap

Ive been searching all day and cant find anything on it.

[Slurpyy]

spec M are you sure there is wiring issues, cause im pretty sure there isnt if you get the closest year "i" harness to your car as you can, should just plug right in, id say about a 2 day job.. 3 if you clean your engine bay area fully and buff it some. before putting the engine in.

[SpecM]

spec M are you sure there is wiring issues,

honestly, no, I'm going on word-of-mouth

[darien28]

the eta uses basic motronic engine management, the "i" uses motronic 1.0 or 1.1 I believe. That would lead me to think that there are different harness connections, but I may be wrong.

Do you have a Bently manual? you should be able to look this up in the manual. If the harness is the same, you'd just need to get the matching ECU for the b25 motor.

[Slurpyy]

If lets say you have an 86 325, and are looking to swap an 87 325i engine in im pretty sure the connectors plug right into eachother, and alot of members from bimmerfest are saying the same thing, as long as the years are pretty much side by side..Its plug and play, remove your e engine put in your i engine plug everything in add fluids crank a few times starts.. test drive??

then turbo.

[Adrian_Visser]

... '87 and later =motronic 1.1, 1.3
earlier = motronic 1.0

1.1 and 1.3 have OBDI

1.0 does not have on board diagnostics.

the ecu on later models is 55 pin the earlier ones are 35.

the c101 connector is different on pre '86 cars

early etas have the fuel filter in the engine bay later cars do not.

if you get the harness and ecu with your new engine you should be fine