[Success Story] 1998 BMW V12 engine M73 #55

[AndreyB]

In OEM form two ECUs are sandwiched one on top of another, with OEM harness not allowing to place ECUs next to each other horizontally.

It's a simple mod: once you remove 21 cm / 8 inches of tape you get enough wire length to place connectors horizontally! With this our M73tu Proteas adapter would be a single PCB!

[bill]

those connectors on both boxes are exactly the same!
how do you keep from plugging the connctors into the wrong box?

[mck1117]

Here's the trick. You don't. The boxes are the same.

[AndreyB]

Do you see the future https://github.com/rusefi/proteus-m73tu-adapter in this preview?

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[AndreyB]

1.5ft of adapter board ordered!

[AndreyB]

Need help:

I will solder Molex 39301020 on my adapter for ETB DC motors.

Question: what part numbers do I need to make harness side to plug into Molex 39301020?

https://github.com/rusefi/proteus-M73tu-adapter/issues/20

[Zeiss]

Hey Andrey,

housing: Molex Mini-Fit Jr. 5557 series 39012020 or 39012025
crimp terminal: Molex Mini-Fit Jr. 5556 series for instance 39000216

Housing should be this one: digikey

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[AndreyB]

Molex stuff has arrived, next step finishing ETB harnesses.

kiwi for scale.

[Zeiss]

It is a pretty huge board!

[AndreyB]

My final test for Proteus units before shipping is a 5 second run on this real M73 engine. Last successful tested batch was about a month ago, without any artifacts.

This weekend I only got one F7 unit to start the engine once. So, let's do proper process.

First data set: new F4 unit
one year old firmware
hard-coded tune https://rusefi.com/online/view.php?msq=782
most puffs were in the beginning and then it would not catch up. too much cranking fuel? what other explanations are possible? https://rusefi.com/online/view.php?log=509

[AndreyB]

Replaced F4 for another F4
all injectors click, both coils click
fuel is flowing
disabled SD card logging just in case

Still some puffs no start. Played with cranking fuel a bit see https://rusefi.com/online/view.php?log=510

[AndreyB]

Simon has pointed out that zero decree is a bad cranking angle - 15 worked much better, also duration adjustment and base fuel settings were adjusted and I got reliable start from bench console "starter relay" button on that old release. This ECU gets an orange sticker is needed so much!

https://rusefi.com/online/view.php?msq=784
https://rusefi.com/online/view.php?log=511

Now I need to hard-code those improved defaults into canned tune before I forget things a year from now.

[Zeiss]

M70 is running with 15° BTDC crank angle in idle.

Which ignitor are you using for the oem coils? I want to try them run with oem coils, before I convert them to COP.

[AndreyB]

Which ignitor are you using for the oem coils?

Camry/Lexus on this harness https://github.com/rusefi/rusefi/wiki/OEM-Docs/Bmw/1998_750_e38/proteus_0.2/Proteus_ready_for_M73.jpg https://github.com/rusefi/rusefi/wiki/Vault-Of-Ignition-Parts

[AndreyB]

Engine has cooled down and unhooked to wall battery charger might have drained battery a bit, one way or another very few puffs again On same tune same unit.

https://rusefi.com/online/view.php?log=512

[mk e]

Engine has cooled down and unhooked to wall battery charger might have drained battery a bit, one way or another very few puffs again On same tune same unit.

https://rusefi.com/online/view.php?log=512

Have you looked at the spark plugs? They can foul pretty quick, I've had to clean mine 6 or 8 times so far to keep all the cylinders starting while I play with tuning setting. Also I just love ether at the early tuning stage, if anything will get all the cylinders started for you its a shot of ether.

[AndreyB]

Those say "BMW Bosch" and take major force to unscrew. Maybe made in 1998? Also too much fuel.

New plugs ordered, I am not beating this dead horse until those arrive. Getting some ether next time I am outside is also a great idea!

[mk e]

Those say "BMW Bosch" and take major force to unscrew. Maybe made in 1998? Also too much fuel.
New plugs ordered, I am not beating this dead horse until those arrive.

Good call, those won't spark.

I have a bead-blast cabinet I use but if you have air harbor freight has a plug cleaner which is basically a tiny blast cabinet if your new plugs end up looking like your old plugs...new gets expensive fast on a 12 cylinder.

https://www.harborfreight.com/pneumatic-spark-plug-cleaner-32860.html

[AndreyB]

Got new spark plugs, got four cans of starting fluid, charged the battery. Cranking fuel 27mg.

Swapped 6 spark plugs because lazy. Did not touch starting fluid. It has started 10 our of 10 attempts, with one of the starts slooooowly building RPM from 250 to high idle.

https://rusefi.com/online/view.php?msq=786
https://rusefi.com/online/view.php?log=513 -< that one has the slow RPM build-up
https://rusefi.com/online/view.php?log=514

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[mk e]

Got new spark plugs, got four cans of starting fluid, charged the battery. Cranking fuel 27mg.

Swapped 6 spark plugs because lazy. Did not touch starting fluid. It has started 10 our of 10 attempts, with one of the starts slooooowly building RPM from 250 to high idle.

1/2 the plugs?.....did both banks start? That slow start was almost certainly several dead cylinders coming on...probably time to have a look at the 6 new plugs, I suspect they don't look new any more, at least that is the battle I've been fighting but I also have leaking head gaskets and it turns out coolant doesn't burn anywhere nearly as well as gasoline. Regardless, keeping plugs clean while getting a smooth idle and on/off starts as you were doing is REALLY hard. Normally it starts and you drive and the driving burns off whatever deposits were created during start and cold idle....so maybe time to have a look at them as looking at the plugs is about the only way to know what is going on in the cylinder before the the O2 sensor heats up and starts reading.

So you're starting code sprays a set amount of fuel while cranking then switched over to the tables once it starts?

I kind of went the other way I think. I do set the main table cranking rpm fuel about 10% high but I use a table that handles prime and start enrich thinking its a wall wetting problem as much as anything else. I've started turning it and it seems to be working but its way too early to say it works good.

[AndreyB]

So you're starting code sprays a set amount of fuel while cranking then switched over to the tables once it starts?

We have both modes selectable - older "designated cranking fuel" and newer "use fueling tables for cranking"

[AndreyB]

[Jhelgesen]

I’m on board. I’ve got a 95 m73 in my 528i. It runs but don’t have rpm over 3k. Trying to understand the eml, don’t have the dash harness so having to jumper the acs and probably the lcm to try to get it to run right.

About ready to pull the trigger on the new ecu.

[AndreyB]

Well for a few years I was making harnesses with VR wires flipped https://github.com/rusefi/rusefi/issues/988

Renaming "60/2 VW" which was recently renamed to "60-2 VW" is now called "60-2 Wrong Polarity", planning to keep it for a few years for compatibility.

[AndreyB]

this has definitely turned to be way more work than I anticipated

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[AndreyB]

A v12 gives you happiness twice: the day you buy it, and the day you sell it.

Sold.