The m20 Motronic m1.3 to m3.3.1 thread - Fully working now!

[HairyScreech]

I wasn't even going to plug them in until I had checked.

The loom was a donor from a friends car, fitted as a replacement after setting fire to his car in exactly this way (he chopped the ABS wire instead).

Funny in someways as I warned him about it before he did the swap only to have him text me a picture of his car covered in powder fire extinguisher 2 weeks later.

[HairyScreech]

That might be an idea.

Think the trouble one might be the ECU side plug I have used to make the upgrade loom plug and play.
I thin the tails of the pins+the soldered wires may be a touch too long to go through.

[HairyScreech]

I can now confirm the loom allows the car to run on the m1.3 ecu as hoped/intended. It's over fueling heavily but the m52 3.5 bar regulator will be the cause as it will give 16% more fuel. Still it allowed me to move it 2 foot closer to the garage and means the ecu should be plug and play.

Next jobs are to get the cam sensor setup for the m3.3.1 built and the lambda drilled into the exhaust, finish off the last 16 wirss to the m3.3.1 and then test the upgraded ecu.

Main concern right now is I have a siemens hot film maf instead of the Bosch hot film maf. I will check the pin outs match as I have modified the plug to fit, just hope the resistance curves are similer. Will have to hunt for the correct maf at some point.

[HairyScreech]

I finished off wiring everything in today, got to do a wire check on it tomorrow and make sure all the wires come out in the right places, just hope it's not pissing it down tomorrow.

I think if all goes well I am about 1 dry day away from getting this running.

Also have an INPA set up capable of reading the older cars now so I can read off the inevitable error codes from the ECU.

If it pisses it down tomorrow I will do a proper update.

[HairyScreech]

Have been dodging the rain all morning and have managed to get the wiring checked, found I had the Lambda sensor wiring reversed on pins 10 and 28 and also changed the crank sensor wires from a separate stub to reusing the E30 wires.

Everything has continuity to the correct pins on the sensor plugs.

12v at ECU checks out ok and all earths are solid.

I have made a temporary earth strap for the coil bodies until I decide how to mount them properly.

Also knocked up a cam trigger wheel in the garage while it was raining. The vanos engines have 50/50 style trigger wheels, like a big half moon.

With that all done I have plugged it in and given it a try with some pretty mixed results.

-injectors are firing ok.
-cam sensor seems to pick up the trigger.
-nothings caught fire
-icv is buzzing as normal
-dosen't start.

With the cam sensor in it's cranking about 3 times and then dead stopping like a misfire/timing out.
With the cam sensor out it cranks out but barely tries to fire.

Seems like the cam trigger is wrong, after a battery charge I will disconnect the cam sensor and give it another go.

I think I might be 180 out on the cam so 360 out on the crank. The change in behavior with the sensor plugged in but away from the trigger is a clue for a start.

Can anyone tell me where the M50TU or M52 cam trigger wheel sits in relation to the sensor at TDC?

[DanThe]

Have you compared your crank sensor/trigger location to the original for the loom? There are two positions for M50, Non Vanos is different to Vanos and if you mix them up it can give the symptoms you describe, like the timing is way out

[DanThe]

This looks to be at TDC

[HairyScreech]

Edit - below post may be wrong, I might have measured a dodgy set up.

Yes they are different but the number of teeth to the missing tooth is the same.

The E30 sensor is on the side at about 10 oclock and the M50tu is vertical at 12 on the timing cover.

However the M50tu trigger wheel has its missing tooth further round on the wheel to match.

I checked previously and worked it out that as long as you kept an M20 trigger wheel and m20 position you were ok, it would only be a problem if the sensor was mounted in the M20 position and the m50tu wheel was used.

Its why the M50 and M50tu/m52 triggers are incompatible, the whole thing is shifted around by about 45 degrees.

It was a bit of a head scratcher to start with as there was a lot of people saying they were incompatible.

[HairyScreech]

Update - Just got the INPA setup working with the M3.3.1 ECU. There is a bit of a bug/omission in the software that means non-EWS ECUs are not read by the INPA because there is a missing file for the older 3.3.1 ECU.
It is available online, Bimmerforums has it as a download if you search for DME331.prg or mistreku.zip.

With that installed I can now talk to the ECU to read the codes.

Unfortunately I only have a "battery disconnected" code as I had to disconnect everything to get the INPA working.

Hopefully will be able to throw a few codes tomorrow but my money is on the cam sync at the moment.

[HairyScreech]

This looks to be at TDC

I think you might be right, I looked at that earlier and was not sure if it was true TDC.

If so then it means the cam trigger is about 45deg out.

Currently my half moon starts at the center of the sensor on TDC.

[DanThe]

Looks like the wheel comes off as the inlet valve is fully open and back on just before TDC for the coil to fire

[HairyScreech]

Having just had a re-read of the M3.1 thread on E30tech it look like the NV version reads 50 degrees BTDC.
Going by that picture it looks like the NV and TU want the cam sensor triggering around 50deg BTDC.


The more I look at it I think your right about the crank trigger, I think the E30 lump I have mocked up in the garage may have a rouge trigger wheel, as i based my measurements off that. I wonder if i have done something really dumb and stuck an m52 crank pully onto the M20 in the garage?

If it is out it looks like an easy fix, the old M1.1 style sensor on the ETA motors mounts somewhere near where it needs to be. Should be easy to mod the front case.

[HairyScreech]

Been through the works with this today, including spending 2 hours in the rain making a crank sensor mount.

I checked it all out and I think Dan is correct with his crank teeth post, I have moved the cam sensor onto a temp mount by the alternator, 5.5 teeth ahead of the missing tooth as per the vanos engines.
Cam sensor was wrong, it was fitted 180 out and did not have the 50 degrees of lead mentioned here: http://e30tech.com/forum/showthread.php?t=63504&page=16

Still no joy though, seem to have fuel but no spark.

Things I am sure of:
1. Its wired up correctly, I have been through it 4 or 5 times now, continuity checks from the ECU plug to the sensor plugs, resistance and continuity check at the ECU plug with the sensors in place and voltage/earth checks at the ECU plug.
2. I am getting fuel, plugs are wet and it stinks after several cranking attempts, not enough to wet the plugs beyond firing though.
3. Battery and voltages are ok, the car was running a few weeks ago on the M1.3 and the battery has been disconnected since (had a charge pack on it as well).
4. CPS is ok, I have tried two different CPS's and have checked the resistance on both, I have also used both on the M1.3 at various times.
5. coils have 12v, coils have earths, coils have continuity at the ECU. Resistance comes out at like 1ohm on primary coil.

I plugged it into INPA and have several errors, two of them are easy and as far as I am aware irrelevant to the no-spark issue, vanos solenoid disconnected (obviously), purge valve disconnected (it is). It tells me the Lambda has multiple faults (I was dicking about with the sensor and the relay, plugged in and out as I was worried about over fueling, it's not inside the exhaust yet).

The ones that are bothering me are:
- All coils bar coil 3 showing open circuit - Its not, I have tested twice, I can beep them out for continuity at the ECU plug, I can also get the correct/same coil resistance at the ECU plug.
Yesterday I checked all of that part of the loom wire by wire and section by section.
- It's puking that the TPS is both open and shorted to ground again it's not, I have checked the loom and the resistance at the ECU, it also varies with throttle movement (new sensor, M52 style), I know I need to adjust it to read the correct idle resistance but that won't cause no spark.
- It thinks the knock sensors are open circuit (again checked) and that they are out of range (plausibility fault)

Now none of these can be possible as the test/checks have shown. I was starting to suspect the ECU but I think I may have been a clown and have just read the ECU cases need to be earthed, it was just resting on top of the washer tank.
Could this have done it or is the ECU toast?

INPA reports no ECU problems, no cranks sensor or cam sensor problems (only checked today, might have complained yesterday) no MAF issues, CLT and IAT are working, ICV is fine.

I have no way of knowing if this ECU is ok as it came out of a scrapyard car but the errors damn seem like an earth fault to me. Can not having the case bolted down and earthed really cause this?

Final thing that is bothering me is that this should be an EWS free red/purple label 413ECU, No spark is making me think this has some kind of EWS, wire 66 is cut in anycase so it should all be fine right?

We are close, very close...

[jmc330i]

Final thing that is bothering me is that this should be an EWS free red/purple label 413ECU, No spark is making me think this has some kind of EWS, wire 66 is cut in anycase so it should all be fine right?

EWS cuts the fuel pump as well as spark does it not?

[HairyScreech]

I think so, I am pretty confident there is fuel there.

EWSII will not let the car even crank, it just clicks so that can be ignored, EWSI I think kills the fuel pump and with no fuel pump running the DME will not spark iirc.

Yes I have been thinking about checking the fuel pump is running during cranking.

[jmc330i]

EWSII will not let the car even crank, it just clicks so that can be ignored

Only if you have wired the EWS into the E30 starter circuit. If you don't, it will crank as normal but won't start due to no fuel/spark.



There's a warning in the wiki about not cutting Pin 66 as it will cut power to the injectors when switching between an EWS silver lable ECU and non-EWS red lable ECUs, which is confusing when there's a lot of US based info saying you need to cut Pin 66

[HairyScreech]

From a bit of research I'm narrowing down some possible suspects:

-Firstly some are reporting the ECU case needs to be earthed or you get odd symptoms, worth a try as this feels like an earth fault.
-Some are reporting that the coils will not fire if the fuel pump is not running, I have no guarantee that it is running during cranking, I will add an LED across the pump to visually confirm.
-Finally the coil earth may not be good enough, it is wired through a previous E30 ECU earth, I wonder if the resistance on that is high enough I am seeing the power from the coils being dissipated via other channels. The coil earth is a 2.5mm cable so I am thinking it needs a hefty earth.

[DanThe]

ECU faults are common with the old M50 now, I've had loads, they are fussy with plug gaps too as I found with the 120k odd mile of running one on LPG and replaced them regularly, about every 10,000 miles.
The coil body should be earthed, through the cam cover bolts on the M50
I can guarantee the ECU case does not need an earth

Have you checked the coil connectors for the signal from the ECU when cranking?

Forget about EWS, the red label ECU's don't even have the circuits for it

[HairyScreech]

Ok, well that's something, no EWS and no case earth to worry about then.
I have the coil bodies earthed via a wire pinched into each of the surrounds and then bolted to the inlet manifold, continuity is fine, will check resistance later tonight to see if it is still a poor earth method, they are not fully mounted yet.

I have not checked the coil connectors for signal yet, any easy way to check this?

Plugs are the e30 ones with the caps/nipples reinstated, they are about 1 year old NGKs gapped to 0.8mm

the multiple errors are making me think earth fault, I am not sure the E30 ecu plug is up to transferring the coil earths from that big 2.5mm wire.

What symptoms were you seeing with the dead ECUs?

[jmc330i]

Dan, what about the wire from Pin 66 that's been cut? Does it have anything to do with the injectors as the wiki suggests?

[HairyScreech]

I cannot see any green or BK/VT wires associated with the injection on either the M50 or M52 diagrams.
Pin 66 is direct to pin 7 on the X20 plug should have no function.

[DanThe]

If you have put an ignition feed into the green EWS wire it will stop the engine from starting

[HairyScreech]

The Green EWS wire is "dining alfresco" at the moment, going to try the earths now.

Edit- earths checked, no dice.
will read the fault codes in a sec.

[HairyScreech]

IT'S ALIVE!

certainly an earth issue, the coil issues went after moving the earth to a solid chassis mount, cam sensor is for sure not right as I disconnected it and it fired up with some pumping of the throttle.

Need to adjust the TPS.
Need to fit the lambda sensor.

[HairyScreech]

I went through the last of the missing bits last night, this meant adding a Lambda sensor to the downpipes, what a bitch of a job with the pipes on the car.
Finding a good location was bad enough and then drilling it and getting a half decent weld was like trying to do your own keyhole surgery.

I sorted out the TPS issue, it was simply that the TPS position was out so the ECU was getting the wrong resistance/voltage. Solved this by adjusting the M1.3 TPS base I had used as a mount.
The E30 tech thread for the NV ECU says to adjust it to 1.38KOhms, The outputs I was seeing on INPA said differently though, when adjusted to 1.38KOhms it was saying 16% throttle and was triggering WOT with about a quarter of the throttle travel still to go.
I will check what I adjusted it to later tonight but I believe it is around 1.1KOhms. Now gives 0% throttle when closed and WOT is triggered at about 80-85% throttle.

Bolted up the knock sensors to the block using the stub between Cylinder 4 and 5 on the exhaust side and the Air con mount stub between 1 and 2. They are in a roughly similar position to the M50TU so we can only suck it and see.

Plugged the purge valve in as well, even though is just flopping about in free air.

I now have no active error codes, The Vanos valve one does not seem to reappear after the first check, it might pop back up upon attempted vanos actuation but from the 413 mapping thread the ECU seems to have distinct maps for advanced and retarded.
http://www.bimmerforums.com/forum/showt ... ing-thread
It may not be such a problem as there are many reports of M50TUs running just fine with the vanos unplugged,
Edit - it actually comes back up once the car is running.

I have the cam sensor unplugged at the moment and it does not seem to throw a code for that either, which seems odd to me.
I know it will default to batch fire and not actuate the vanos without this but it seems strange it does not throw a code for it.
The next thing to work out on that front is if the sensor is not picking up the tirgger, if the trigger is in the right location and if the M54 sensor will play happily with the M50 ECU (both 12v hall sensors so should be happy).
Edit - soon as the car is running it does throw it up as a code.
I have a massive fuel leak at the moment so I need to fix that tomorrow, once that is sorted I will plug the sensor back in and give it a bash.

I have found the cause of my poor/nearly impossible starting, the fucking MAF from EBay. Once it was running the INPA instantly threw up a code for the MAF, swapped it out with one I had from a 328 (plug is modified so I can fit either) and it fires instantly now.
Its running rough so far so I need to do a bit of work.
Next thing to do is get hold of a stock M20 map on an M3.3.1 chip and see how it behaves.

Seems I have been chasing a MAF fault all along.

[HairyScreech]

Spent a few more hours on this over the weekend (read 15 hours) and I can only report that it all now works.

I changed the fuel hoses out as the old ones were perished and leaking,
The ICV was wired up backwards, had it on right the first time, It was hunting from 1500-2500 until I swapped them back. (The opening and closing coils are not marked on the E30 diagrams).
The MAF was not getting a good steady 12v so I moved it from being powered with pin 87 of the Lambda relay to Pin 30 giving it a permanent switched live.

The Cam sensor is now actually working fine, somehow I screwed up the change over plug, with the trigger on at a 50 degree BTDC lead and the M54 sensor powered up right I have no cam sync errors and no plausibility errors, Infact I am down to just a vanos solenoid disconnected and a Knock sensor error.

I did manage to get the plugs through the hole and it's all now tucked up under the dash. The result is this:



http://vid159.photobucket.com/albums/t1 ... xwxasj.mp4

[youtube]http://vid159.photobucket.com/albums/t1 ... xwxasj.mp4[/youtube]

[jmc330i]

Good work

[Brianmoooore]

Excellent work! You won't get a steady 12 volts from 87 of the lambda relay - that only switches on when the lambda sensors are below operating temp.
Connecting it to pin 30 is connecting it to one of the switched outputs of the DME relay, so live all the time the ignition switch is on.

[HairyScreech]

Excellent work! You won't get a steady 12 volts from 87 of the lambda relay - that only switches on when the lambda sensors are below operating temp.
Connecting it to pin 30 is connecting it to one of the switched outputs of the DME relay, so live all the time the ignition switch is on.

Yeah I realised that when I checked the supply voltage, For some reason I thought it was an always on relay.

Pleased with how it revs for a cold standard M20.

[HairyScreech]

Right, given this is now all running and stuff I need to sort out the tune on it.

After looking about there seems to be few willing to take up the challenge so as usual I'm just going to learn to do it myself.

Have picked up tunerpro, a copy of the 413(3.3.1), 402(3.1) and 173(1.3) .bin file, a copy of the definition file for each of the ECU .bins and started reading.

Will post the files up here later tonight once I am back home

[HairyScreech]

Just ordered myself an ostrich to start on this, http://www.moates.net/ostrich-20-the-ne ... l?cPath=95

Allows realtime tuning on the Motronic ECUs, works for the M20,M50 and M50TU, should also work for the M60/62 and most of the M engines. Handy little device.

Chip burner and some EEPROMs coming as well.

[HairyScreech]

For the benefit of a couple of people that have asked what I have been using to look at the maps...

The software is TunerPro http://tunerpro.net/ This is a free/shareware program that can view a lot of ECU maps from the Pre OBDII era.

It relies on having a definition file that matches the chip/software revision in the ECU, these are in .XDF format and can be found for a lot of the common BMW stuff. Tunerpro hosts a set of these along with the matching .BIN ECU files.
If in doubt you can just base your new ECU tune on the example .BIN.
http://tunerpro.net/downloadBinDefs.htm
http://tunerpro.net/download/bins/BMW/

I won't claim to really know what I am doing with it all yet but I will be posting what I know here as I go along.

For this ECU I have been working from their stock173.bin and the 413 red label BIN.

So far it seems the ignition timing of the M20 is about 5-9 degrees advanced vs the M50 and the fueling is much less on the M20.

While I am not sure of the exact units of some of the values in these maps the two ECUs are based on similar architecture and seem to require similar inputs.

The load on the M20 is calculated quite differently from the M50, that is expected knowing the differences between the AFM and MAF system.
The M20 173 ECU uses the AFM for most of its load while the M50 402/413 ECU uses a value calculated from the MAF and the TPS, I believe there may be some other factors in the load, like the engines acceleration rate and the knock sensor response, The load seems to be an abstract value for this ECU and noone seems to be able to tell me what the value actually relates to.

In practice it doesn't matter, there are 12 load values going up to WOT and that is all you really need to know to modify the tune.

[jimbom30cab]

Awesome thread and great work

Very much looking forward to the tuning updates

Thanks