E30 m40 to e36 m42 wiring

[Langer]

I'm half way through an engine transplant but have been stumped by the wiring. I've done the usual sump changing and ex mani etc but couldn't get the e36 inlet mani to fit because it was hiting the brake servo??? It would have been nice to get it running with all the original parts connected with the engine but luckly i'd already purchased an e30 one so that will go one once the wiring is sorted but this is the PROBLEM, the main loom connectors (101c?) are completely different . I'm presuming the m40 loom won't work because of the m42's coils/ knock sensors etc. Is it just a case of cut and shuting the m42 loom to fit to the m40 main connector or can i get around it by another means? The motors from a 92 model e36 AUTO if that makes much difference (park sensor?) This has probably been asked before but after alot of reading and googling i still can't find the answer i'm looking for Any help would be greatfully appreciated as it's now stoping me getting it completed. Cheers

[eko]

Probably much easier to just fit an E30 M42 engine loom.
User by the name of Magpie had one for sale recently I think?

[rix313]

Probably much easier to just fit an E30 M42 engine loom.
User by the name of Magpie had one for sale recently I think?

+1 buy and fit an E30 loom and job done.

[Langer]

Ok cheers what about the knock sensors?

[rix313]

E30 engines don't have them, so I doubt the E30 ECU has the provision to use their signals so don't plug them in (not that you can any way, as like I said, it wasn't part of the E30 system).

[Langer]

The engine, loom and ecu are from an e36 with the knock sensor. So What i'd need to do is fit an e30 loom to the e36 engine minus the knock sensors (as you said no provision for them) and this would work with the e36 ecu because it would just think there is no det or pinking right?

[rix313]

What engine was fitted to the car and what year is it?

[Brianmoooore]

Changing the engine loom plug on the E36 M42 loom to fit an E30 C101 socket should be very much the same as changing the plug on an E36 M50 loom, which is well detailed in the M50/52 section.

[78gizmo]

'Calmac' on here has just posted in parts for sale an E30 318is ECU for £30, just add E30 318is engine loom and plug it all together, job done!
I am doing an M42 conversion to my M40 at the moment, trying to find time to finish it off. I am told they respond very well to a better exhaust and chip.

[Langer]

The original motor was a 316i m40 with a dizzy type ignition so the old wiring dosen't have anywhere to plug the m42's coils in??? I'm thinking i'd need e30 m42 wiring and ECU then.... but could also cut the wiring to fit the c101 connetor as Brian said to get it running. Thanks for all the help guy much appreciated!!! Hopefully get somewhere with it tonight

[Langer]

Oh and the car was originally a 90 316i "lux"

[Brianmoooore]

This should be of some use:

M50 1/ blue/white (dynamic oil level) E30 2/green/yellow
M50 2/ blue/yellw (static oil level) E30 10/blue
M50 /3 red/white (ABS) E30 20/ red/yellow
M50 4/ black/blue (aircon) E30 not used
M50 5/ black/grey (aircon) E30 not used
M50 6/ purple/grey (aircon) E30 not used
M50 7/ black/purple (drive away) E30 not used
M50 8/ grey (engine check light) E30 12/ grey
M50 9/ NC
M50 10/ NC
M50 11/ brown/yellow (water temp) E30 not used
M50 12/ brown/purple (water temp) E30 4/ brown/purple
M50 13/ green/purple(fuel pump) E30 13/ green/purple
M50 14/ black/white (speed) E30 14/ black/white
M50 15/ black/green ( unloader relays) E30 15/ black/green
M50 16/ white/yellow (Rx data) E30 not used
M50 17/ white purple (Tx data) E30 not used
M50 18/ black/yellow (starter) E30 18/ black/yellow
M50 19/ white/green (service reset) E30 11/ white/green
M50 20/ black (engine speed) E30 9/ black
M50 21/ green (ignition) E30 7 green
M50 22/ green/white E30 6/ green/white
M50 23/ brown/grey (oil pressure) E30 5/ brown/green
M50 24/ white/black (fuel rate) E30 8/ white/black
M50 25/ blue (ignition warning) E30 1/ blue

[Langer]

Thank for the help guys. Managed to get the thing to turn over and spark and the fuel pumps pumping fuel but then something earthed and now nothing . Thinking it's a dodgy wire from the starter hopefully shouldn't be to hard to figure out. Friends modifying the e36 exhaust to fit so should have it running this weekend . Anyone had one of these running on bike throttlebodys? Any info?
Cheers

[Jos]

Just about to do exactly this swap. Engines are out of the 2 cars. I am going to mod the e36 exhaust manifold to suit, thank f**k it's stainless!

Langer where did you put your ECU? Did you extend the loom?

The pinouts are what I have from the 2 ETM manuals (less a few), I'm going to make a go-between cable using the C101 from the M40 loom and the X20 connector from the e36 chassis, the only alteration I am doing is to use pin 3 on the C101 to run to pin 7 on the X20 for EWS (have keys, module, loop and all the other gubbins). Any issues with this?

[Langer]

Everything went back in ok tbh with a little faffing. Had to change the power steering pump mount to the E30 one and use the E36 wheel for it to get the belt to line up. I used the E36 inlet manifold in the end as the injectors from the E30 one i bought were buggered and had no problems with the bonet hitting although i need a longer throttle cable possably the E36 one will fit??? The inlet is a little close to the brake servo res and can just be manipulated into place. Coils need a bracket making as does the airbox but that not a biggie. The wiring wasn't to much of a problem in the end but as you say the loom is a little to short to get the ECU back to where the original was, i've manage to get it in but it's not ideal (had to cut some plastic trim). Off the top of my head thats it. Mines all in now and running sweet just need to sort the rough edges and get some more power
Hope that helps, good luck

[78gizmo]

Did your E36 exhaust need much modding? I am struggling to get an E30 M42 front pipe (have got the manifold) to complete my M40 to M42 conversion, but have seen an E36 M42 front pipe/cat for sale and am wondering if it can be made to fit?

[Langer]

I cut the cat off the E36 system and modified the front section so that it would fit around the lower control arm and used the rest of the system i had. It can be done quite easily if your handy with a welder or know someone who is.
Hope that helps.

[e30yttocs]

can someone please help ive follwed your wiring diagram and i dont seem to be getting any spark