Running M10 on m42 Motronic

[E30SPDFRK]

Frustrated with the lack of options for m10 tuning, I had the thought today of running an m42 harness and DME. They’re both 4 cylinders with the same firing order, Both run the same style injectors, both have AFM’s, roughly the same sensors.

Has anyone done this? Any thoughts into the subject? It would probably need a new chip to run correctly, but that’s easy enough.

[e30davie]

Can you tune the M42 DME if you get it to work?

issues i see -

- Adapting whatever crank/cam signal the M42 uses to the M10
- The M42 uses an air flow meter yeah? if you use the M42 air flow meter will it care that its probably oversized for the m10? ie it might only ever open 50% as the M10 cant physically pull as much air as an m42.
-what you gonna do about ignition? M10 use a vacuum advance distributor yeah? So you either leave the dizzy alone, or you lock the distributor, grab a generic Bosch ignitor to control the ignition externally (I did this on a Suzuki engine once). OR you convert to coil on plug like the M42.

If you intend on tuning anyway, why not get a Mega squirt 2 kit, make your own loom to suit the M10 and tune that?

Then you can run it on Map sensor for starters (air flow in the bin), and you can choose whatever trigger is easiest.

If you use the internal map sensor, you might only need like 10 wires to run the engine if you go the lock the distributor route as discussed above.

[TobyB]

Mega squirt

was my thought as well.

The M42 wants a crank sensor, a cam sensor, knock sensors if you use E36...
but everything else will probably work.
I bet the stock M42 maps would start and run an M10,
but then you're stuck with 25 year old technology at best.

It just doesn't seem like much of an improvement with the flapper door.
I guess you could use M44 hardware to get a MAF, but that's OBD2,
with EWS and more stuff to mess with.

Nope, never tried it.

t

[thebutterson]

I started a project similar to this on my M10 using Volvo LH Jetronic parts but abandoned it for a Microsquirt system for several reasons:

-It was going to require a 60-2 wheel which was harder to find for an M10 than 36-1, which was easily ordered from 02again.com

-Tuning required and Ostrich 2.0 system to tune the car, and a chip burner. The tuning setup was about the same price as a microsquirt unit and harness. Also, it ran two computers, one for fuel, one for ignition. You wouldn't have that problem running M42 motronic, but will still need the Ostrich to tune.

-Microsquirt uses a lot of easily available GM parts and has provisions for you to use your own sensors for temperature if you want. MAP sensors are only ~$30, much cheaper than AFMs or MAFs.

Like others said, your hurdles are the crank sensor, cam sensor, and tuning. If you can solve those relatively easy then its a viable solution for you.