[W126 Coupe] W126 Engine ideas

[Josh Allen]

David,

As Axel mentioned, tuning any replacement ECM is a major undertaking.

If you can find one that someone else has already done the majority of 
the work tuning, and that you can get a copy of their tune, you can get 
a large head start though.

I've been playing with a Megasquirt ECU, and there are a few people who 
have installed them on m116 and m117 engines, most have also shared 
their tune data.
That being said, you have to take any tune with a bit of caution, as you 
don't know exactly how it'll behave with your car.  It's just a jumping 
off point to fine tune it to your vehicle.

Also, if you're not personally going to be doing the tuning, you need to 
find out what a local tuner is willing to work with.
For me, the closest tuner that has a decent reputation detests 
Megasquirt, saying it's for hacks and shade tree mechanics only.  (It 
also doesn't make him a good bit of money on the sale of the hardware, 
or the tuning lock in due to the expensive tuning software...)

Any which way, do a good bit of reading and research first.

As to the existing 5.6l engine, I would think that since you have the 
engine sitting there you could easily build the wiring harness for it 
without needing to 'break' the running car, and when ready to install 
the engine just swap the whole thing in, make the required connections 
to the new wiring, and be up and running in fairly short order.


Some reading for the MegaSquirt ECU:
http://www.megamanual.com/mtabcon.htm <===  THE book of MegaSquirt
http://www.msefi.com/index.php
http://www.msruns.com/viewforum.php?f=106&sid=e1bd3f54846b34bce380a4a4a15d91b9 
<http://www.msruns.com/viewforum.php?f=106&sid=e1bd3f54846b34bce380a4a4a15d91b9>

Vendor who supplied my MS hardware (there are many others as well)
http://www.diyautotune.com/


Happy reading, and best of luck whichever route you choose!

-Josh Allen