87 325i engine into 91 318i

[SM AUTOS]

Hi all

Has anyone completed this conversion?

I have the doner 325i which i'm pulling to bits at the mo, and just trying to get my head round what I need to swap.

The wiring inparticular has me scratching my head..can anyone offer any advise?

Am in the process of swapping brakes suspension etc, so any information would be appreciated before I jump in at the deep end.

Thanks in advance

[Brianmoooore]

No problems with this conversion! If this is a pre face lift engine, then ideally you change the front pulley, engine loom, pick ups, etc., for those from a facelift 320 or 325. This will give you an improved, more reliable management system, with a loom that will plug straight into your existing car.
Conversion can still be done with the pre facelift set up with the pickups in the gearbox bell housing, but the plug on the engine loom will need changing for the later type.
The 325 air filter/AFM won't fit the 318i bracket without mods, and you'll need the mounts for the 325 coolant bottle as well.
Refurb and swap over the complete rear subframe with suspension, and either swap over the front legs, or the complete frame again.

[SM AUTOS]

Thanks alot for the advise it's really appreciated.
The engine is now ready to come out of the 325i, I've already sussed that the mounting for the expansion bottle is missing and the airbox won't fit on the 318i mounting

As far as the wiring goes I have removed the 325 ecu and loom and thought I could probably work out the wiring at the round plug under the bonnet......however the 325i loom has 11 pins and the 318i has 13...am I barking up the wrong tree? Is it possible to do it this way? Seems like alot less work then swapping all the engine sensors for later type ones?

I thought I read somewhere that only some of the wires need connecting for the engine to run?
Both cars have motronic systems on them if it helps.....

[Brianmoooore]

The reason for changing the engine sensors over and using a facelift loom is that the early type ECUs are a very primitive and not particularly reliable computer. Engine management will be better using a later ECU.
The wires from the engine loom to the car are basically the same - just a different plug.
Only wires needed to make the engine run are: ignition live (green), fuel pump feed (green/purple) and the starter signal (black/yellow).

[SM AUTOS]

Brianmoooore your an absolute star!

I completely understand about what your saying re the early ecu, I know there not upto much To be honest I just wanted to get the engine in the car and running, and it was the wiring that was causing me some headaches.

Regarding your information about the wires and colour codes that it exactly what I needed to know, thats why the E30 zone is soooo good, there is always someone that knows far more then us newbies.

You don't by chance know what any of the other wires do do you?

Thanks once again

Steve

[Brianmoooore]

I know what all the other wires do! Most of them are for instrumentation of one kind or another.
There are posts in the archive section of what they all do, or post any here (colours) that you are unsure of.

[SM AUTOS]

Thanks for your help, I will get back to you if I get stuck

[SM AUTOS]

Hi Brian,

The engine is in and running, the two halfs of the connector just plugged together and it runs fine, all dash lights work etc..

The only 2 things that dont work are the rev counter, which has two seperate wires coming off near the old ecu, I guess I can just connect these up to the revcounter?

And also the blower motor doesn't work, any ideas or have you come accross this before?

[ShepsEvo3]

May have something to do with the rev counter in your car is still for the 318? 4 cylinder. Unsure, but I think you will need the rev counter from the 325i? Unless you've changed that already?

[SM AUTOS]

Rev counter doesn't work at all....I have kept the old clocks out of the 325i so will try swapping them over and connecting them up

[SM AUTOS]

Right, have swapped the chip over in the clocks and wired the rev counter up and all works now

I do have another problem though, the heater fan sometimes works sometimes doesn't. I have the same problem with the electric windows and mirrors, when they work they all work, and when they don't none of them work

The horn & the reverse lights don't work at all

I just connected the round engine plug but obviously the 325i engine loom & 318i fusebox aren't quite the same.

I've checked the colour of the wires some match up and some don't, but I thought these were more to do with the instrumentation

Before anyone asks I have done a search and found nothing to help me much.

Any ideas greatly appreciated

[Brianmoooore]

Windows, heater and mirrors are all powered through the unloader relays K5 and K7, which cut the power to these things when the starter motor is used. The relays are switched by a black green wire which goes through pin 15 of the engine loom connector and goes to the smallest terminal on the starter motor, where it is earthed, except when the starter is used.
Horn is nothing to do with the engine transplant. Pull out relay K2, and like together pins 30 and 87 of its base with a short piece of wire. What happens?
Reverse lights: Find a white two pin plug and socket to the right of the base of the gearlever (under the gaiter, inside the front console. Pull the plug apart, use a piece of wire to link together the pins of the half that DOESN'T go down through the gear lever grommet. Turn on the ignition. Do the reverse light come on?
Several wires change colour from one side of the engine loom connector to the other.
If your engine loom and car loom plug together, the connections are the same, although the 325 side may have more wires.

[SM AUTOS]

Thanks again Brian.

I'm not too bad at wiring & fault finding, but it makes life easier if I know where to start looking

I will have a look at the car and let you know how i get on.

Are you some sort of wiring genius when it comes to E30's?

[sideways_king]

Brian i have a similar problem!

i have a pre face lift 87 325i manual and i want to put the engine and gearbox in my auto face lift 90 325 sport as the head has gone on the sport.

i have had a look and i think i need to change the inlet manifolds over as the plugs are different, OR should i change all the engine wireing and motronic unit thing over as there is an extra wire for the starter motor in the face lft 90 and some plugs are different? im not sure what i need to do so some help would be greatly appriciated!

also do you know how i get around the inhibitor switch?

many thanks
Ashley

[Brianmoooore]

Swap the engine loom and the front toothed wheel etc. from the later engine onto the early one.
I've never done this personally, but I've never heard that the inlet manifold has to be changed. The only wrong connector is for the oil pressure switch, according to what I've read previously. Possibly the oil level sensor needs to be swapped as well.
Inhibitor switch: Above the glovebox there are two single pole plug and sockets with black/yellow wires. Unplug these, and plug together the two black/yellow wires that come from the main loom. The other two wires can be removed, along with a relay and some wires that go to the centre console. (All in a seperate sub-loom.)

[sideways_king]

brilliant thanks!

Do i need to change the motronic unit thing under my steering wheel as the plugs to connect to it is different?

i really appreciate this as my car has now been off the road for about 3 weeks and im starting to mis it really bad! ! !

[Brianmoooore]

Yes, you definitely need to change the ECU under the steering wheel. That's the whole point of the change.

[sideways_king]

Hi again Brian.

ive now done the engine swap and its not running?

the starter doesn't turn over at all, no clicks or nothing!

there is a black ten pin plug under the steering that no longer has anything to connect to as well as a white three pin plug that no longer has nothing to connect to. any idea's? ?

also my heater blower doesn't work at all and my sunroof and windows are temperamental. also my batt light and the orange light with the ! mark in it are very faint. when i turn the key from ignition on, to try and start her the batt light disappears and does not come back on for a while? ?

i am very confused and desperately need help! ! ! ! !

many thanks

Ashley!

[sideways_king]

Sorry brian i missread what you wrote.

im now in the process of changing the loom. will update shortly

many thanks

Ashley

[sideways_king]

hi Again brian.

Everything is done but she still wont start. ive took the fuel line off and there is no fuel getting through!

Any Ideas? ? ? ? ?

[sideways_king]

also cant hear the fuel pump at all!!!

many thanks

Ashley

[Brianmoooore]

Does the engine turn over on the starter?