M20 cylinder identification sensor (CID) and Aftermarket ECU

[zaq123]

Those of you with aftermarket ECUs, Do you have CID signal configured for anything? If so, what were those parameters? CID is neither hall nor reluctor how I understand it so I lost a little. Or you guys ignore it and just have all injectors pulse simultaneously all the time?



Is this decription even accurate on how CID signal is being configured for stock DME (link) https://www.e30zone.net/e30wiki/index.php/CID

[e30davie]

it depends how you set up your system. I don't think you'll get the CID to connect to an aftermarket ecu unless you find some sort of external conditioner to make it into a digital signal for the ecu.

if you use the 60-2 wheel, and the distributor the distributor takes care of the sequential ignition. and you run the injectors in alternate fire every revolution but they only squirt 50% of their fuel. and the ecu doesn't know which one to fire but it all evens out. Arguably you could put a cam shaft sensor hre in place of the CID sensor, but i don't believe there will be much benefit.

if you use the 60-2, wheel without the distributor you either have to run the ignition via wasted spark using 3 igntion outputs and 2 groups of 3 injectors like oem (as the ecu doesn't know which 360deg of the 720deg its on), or you install a camshaft sensor, which they often refer to as a "reset" and you run full sequential requiring 6 injection outputs and 6 ignition outputs.

the CID sensor is a cheat way to tell the oem ECU when its at TDC, but the aftermarket ecu will operate without it. Id ignore the CID all together.

note: I made a whole new loom for my megasquirt install. wasted spark with 6 coils. I cant remember how I wired the injectors, but it was 2 groups of 3. no CID or reset required for this arrangement.

[zaq123]

I'm trying to wire Haltech into mine. I'm just trying to understand what input signal will need to be selected as Home? Trigger is obviously crank sensor but what about Home :)

[e30davie]

As per above, depends how you wire it up and your control strategy. you might not need the home.

There is no "home" on an m20 by default. you have to do a custom one IF you want to use it. example:

https://racehead.com.au/product/bmw-cam-sensor-trigger-kit-m20-m30-m88/

[zaq123]

I really want to stay with a distributor actually.. Wasn't sure if to run Haltech you absolutely need Home signal or it can be set like in MS, unlimited injection.

[e30davie]

Youll have to read the haltech manual to figure that out. Almost guaranteed you dont need the home signal though if you want to use the dizzy though. youll only need 1 ignition output, and wire the injectors in a way that haltech allows (from an output allowance perspective)

[zaq123]

yeah. Looks like Haltech Nexus software has an option to run semi-sequential from just VR at the crank with 60-2 wheel. My tuner confirmed. Will be interesting.

[e30davie]

If you are going to all this trouble you should get rid of the distributor....no more moving parts. 6qty ls1 coils wired in wasted spark and 3 ignition outputs - done.

the main issue is finding a nice place to mount them...I put mine where the battery used to go.

[zaq123]

Id like to keep some originality on this built minus ITBs (which may or may not remain on this car). Plus there are zero performance gains with canning the distributor. Moving parts - yes but it's not a daily driver.