Engine Pre-face lift into facelift

[Dave2207]

Hi new to the forum and looking for some help please...I have fitted a pre face-lift 2.5 engine into a face lift 318 and as I am sure you will know I have ecu issues, also how do I get round the radiator fitment, do I install a pre-face lift unit or a face lift One?? Many thanks if you can help with this.

[Brianmoooore]

as I am sure you will know I have ecu issues,

???? This is apparently your first ever post, so why do you think we know about your ECU issues?
If you used the matching loom and ECU for your engine, there should be no issues at all.
The easiest radiator to fit would be the matching pre facelift 325 radiator and remote header tank on the RH inner wing, changing the lower radiator mounts for the appropriate ones. If you change the water pump for a facelift M20 one, you will be able to fit the later 325i radiator, 'tee' hose and header tank on the LH wing, or, with a bit of ingenuity, and juggling of lower radiator mounts, E34 and E36 radiators with the header tank on the end of the radiator, can be used.

[Dave2207]

Hi thanks for that I think it might be easiest to change the water pump...is it a straight foreward swap??
On the engine loom the pre-face lift has two rows of pins and the face lift has three rows, the car will crank but no fuel or spark.
I am doing this for my son and it was last summer I last looked at it but he is bending my ear to get it done now,these are the only issues that stumped me.

[Brianmoooore]

3 rows of pins suggests that this might be a facelift M20 engine loom that you are using, in which case you will need to use a facelift M20B25 ECU, such as the 173 (most reliable) or 380. The equivalent M20B20 ECUs can also be used as well, provided the main 'chip' is replaced by a 2.5 one, which can be a mildly 'uprated' one from the likes of Speedtouch on here.
Water pump is a straightforward swap, although the tensioner spring for the cam belt makes things slightly difficult, so if a cambelt change is due, this is the time to do it. The only difference between the pumps is the lack of the stub pipe for the header tank on the facelift version.

[Dave2207]

Thanks for that Brian, yeah good idea on the Cam belt, I have the two rows of pins on my engine loom there are three wires separate from the ecu which plugged into the car on the pre-face lift but don't have a home on the facelift, I wondered if they are a power feed for the ecu or something else, I will put a meter on them to see if any of them are live.

[Speedtouch]

You could alternatively retain your pre-facelift loom and use the matching 0 261 200 073 ECU...