E36 ECU

Greyfoot

Alright so, finally got my head around swapping the engine in my 320i. I bought a donor 525i a while back and last sunday did the swap.
The problem is that the e34 was auto.

The car fires up and working with the 320`s ECU but I think the engine might run lean. If I stick in the ECU from the 525 then the idle all messed up since it came from an auto.

My question is if I get the old 320 ECU chipped will it alter the ignition tables accordingly with the 2.5 lump or not? Should I go ahead and source a 2.5 ECU instead?

Thanks in advance.

Plug

Is the 525 a 6 cylinder if so I'd try and source an ECU for a 525 manual.

Greyfoot

Plug wrote: »

Can you source a 2.5 ECU that came off a car with a manual? That engine and box wont run right.

Might be able to get one alright was thinking to save some money here.
Will I be better off using the 2.5 auto ECU for the time being?

Master and commander

Depends, is it a self learning ECU?? if yes then it might run lean or rough for a few minutes but take it for a spin and it should re-calibrate its settings via the lambda and then run fine.

Greyfoot

Master and commander wrote: »

Depends, is it a self learning ECU?? if yes then it might run lean or rough for a few minutes but take it for a spin and it should re-calibrate its settings via the lambda and then run fine.

How do I know if it is or isnt? Its a Bosch unit Motronic 3.1 if memory serves right.

Master and commander

No idea, its just something you 'd have to research. Maybe contact someone in bosch or BMW and they might be able to find out( not the mechanics, most of them are dumbasses "thaaa cumpuuter saaayys ......noooo" types)

Plug

I wonder though an ECU for a 4 cylinder engine used on a 6 cylinder. Not really the best idea in the world.

Greyfoot

Plug wrote: »

I wonder though an ECU for a 4 cylinder engine used on a 6 cylinder. Not really the best idea in the world.

Well, these bosch modules are used in most early models I think its just the software thats different on them.
I am not sure what you meant but the 320 and 325 are both 6 potters.:rolleyes:

Plug

Greyfoot wrote: »

Well, these bosch modules are used in most early models I think its just the software thats different on them.
I am not sure what you meant but the 320 and 325 are both 6 potters.:rolleyes:

I thought the 320 was 4 pot, my bad.
Im not sure if the ECU is a self learning one. As Master and commander said contact Bosch or whoever makes the ECU they should confirm it. if its a self learner you might get away with it. Is it still running how you described it first?

Greyfoot

Plug wrote: »

I thought the 320 was 4 pot, my bad.
Im not sure if the ECU is a self learning one. As Master and commander said contact Bosch or whoever makes the ECU they should confirm it. if its a self learner you might get away with it. Is it still running how you described it first?

320i ECU is in the car atm everything seems good so far, power output nowhere near 190hp though...:(

Gary ITR

Master and commander wrote: »

Depends, is it a self learning ECU?? if yes then it might run lean or rough for a few minutes but take it for a spin and it should re-calibrate its settings via the lambda and then run fine.

A self learning ECU is one thing, but this would need a completely different Map. I'd try source one for a manual 525

muckeyw

Guys guys guys I do theses jobs everyday it won't work as it's a auto ecu the u need a ecu out of a standard manual and the same model and even then u could run into problems having things mached up. U just need to sit down and think it out but I defo reckon your gona need to get some checks done on the BMW gt1

Greyfoot

muckeyw wrote: »

Guys guys guys I do theses jobs everyday it won't work as it's a auto ecu the u need a ecu out of a standard manual and the same model and even then u could run into problems having things mached up. U just need to sit down and think it out but I defo reckon your gona need to get some checks done on the BMW gt1

The car runs fine with the auto ECU apart from the high idle. Also runs fine with the ECU from the 2l engine I suspect it might runs lean though.
I reckon if I get a manual ECU from an ews1 2.5l it will be fine.

Still the engine runs with the 2l maf and pipes as the rubber boot for the 2.5l is disintegrated over time and the diameter of the intake line is smaller that of the 2l so that needs to be sorted out too.

muckeyw

u might think it runs fine but i bet you there will b under lying problems im just tell you as it it best to get the right ecu and then c how it preforms but things are never that straight forward

crosshair1

These will run pretty well on a 2.0 ecu but will be underfuelled, years are important as up to 93 doesnt have ews, or single vanos.
If you get an ews1 ecu then Im pretty sure you will need the relay from behind the passenger speaker(e34) and I'm not sure if that is compatible with the e36 central locking.
Muckeyw might be able to clarify this.
It may also be worth getting the wiring diagram for the auto ecu as its possible that there is just one switch missing, similar to one with/without aircon and all you would need to do is bridge 2 wires/pins on the ecu to fool it.
From memory of swapping a 2.5 into a 2.0 e34 there is one or two wires short in the ecm plug, this was a long time ago, cant remember what for but overlay diagrams and you would find out.