Megasquirt ON BMW m52 Engine

General support questions and announcements for MS3. See also MS3 manuals.

Moderators: jsmcortina, muythaibxr

maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

jsmcortina wrote:Can't you just wire it up in the normal way like in the manual ?

James
its harder way when this one... :roll:
hoveringuy
Experienced MS/Extra'er
Posts: 172
Joined: Fri Aug 29, 2008 8:52 am

Re: Megasquirt ON BMW m52 Engine

Post by hoveringuy »

jsmcortina wrote:Can't you just wire it up in the normal way like in the manual ?

James
Yes, but one way or another IGN power isn't sufficient for main power and a relay must be used. The BMW already has a nice main power relay, but the stock ECU sends a ground signal to trigger it. Therefore an NPN is required to create a ground signal from IGN.

It works very nicely and there's not an extra relay floating around.
maxo-tt1 wrote:hello people...

have one problem about start circuit.. i use my siemens wiring, and reley are different. can someone help me modify diagram above ?

that diagram says that on bosch relay 30 and 86 are battery voltage.

on my siemens reley i got voltage in only 87

this is my reley... maybe someone know how to remake it ? :(
It looks like you would just switch 87 with 30. Megasquirt will get power from your relay pin 30.
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

maxo-tt1 wrote: It looks like you would just switch 87 with 30. Megasquirt will get power from your relay pin 30.
aha, Thats right. but what about 85 and 86? i need to get +12v on 86?

and on your power diagram, power goes from collector into pin 27 or from 27 to collector?
jsmcortina
Site Admin
Posts: 39569
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Megasquirt ON BMW m52 Engine

Post by jsmcortina »

hoveringuy wrote:Therefore an NPN is required to create a ground signal from IGN.

It works very nicely and there's not an extra relay floating around.
Fair enough, however for some installers a relay might be easier and more robust and doesn't involve fiddly electronic components.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

and one more problem(i think)

i get +12v on coil PIN-s of bmw 88 pin connector

as i know on that pins megasquirt provides ground yes?

and also on injector PINs... comes 12v...

is it normal? :shock:
protomor
Experienced MS/Extra'er
Posts: 367
Joined: Wed Feb 28, 2007 7:13 pm

Re: Megasquirt ON BMW m52 Engine

Post by protomor »

The coils should get 12v to power them. Then the MS sends a low volt signal to them to ground them out. There are 3 wires that go to the stock coils. 1 is power, 1 is signal, and 1 is the signal ground (no 4th because the body of the spark plug grounds through the engine head). I haven't read how you are outputting spark but it gives a signal not a ground.

The Injectors on the other hand will get power when the ECU is on and the MS grounds them.

does that make sense?
-Yoshi-
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

protomor wrote:The coils should get 12v to power them. Then the MS sends a low volt signal to them to ground them out. There are 3 wires that go to the stock coils. 1 is power, 1 is signal, and 1 is the signal ground (no 4th because the body of the spark plug grounds through the engine head). I haven't read how you are outputting spark but it gives a signal not a ground.

The Injectors on the other hand will get power when the ECU is on and the MS grounds them.

does that make sense?
aha, you're right. but in signal pin comes 12v, where ms sends low volt signal... and this voltage goes in MS3x coil pins... thats why i think that there is not everything ok...

and when i check injector, in both wire comes 12v... from signal as well... :cry:

here on img 3 coil pin, where ms should send signal, but on this pins comes voltage (with stock bmw confiuration... i've changed nothing... just switched off ECU and tested pins with multimeter)
protomor
Experienced MS/Extra'er
Posts: 367
Joined: Wed Feb 28, 2007 7:13 pm

Re: Megasquirt ON BMW m52 Engine

Post by protomor »

I'm not quite sure what you mean.

You can do this with the stock harness. I've seen others do it. I made my own harness though. The injectors should have 2 wires. 1 is a power, the other goes to the MS. That's really all you need.

The coils are similar. 1 should be power, 1 should go to the MS and 1 should ground.
-Yoshi-
hoveringuy
Experienced MS/Extra'er
Posts: 172
Joined: Fri Aug 29, 2008 8:52 am

Re: Megasquirt ON BMW m52 Engine

Post by hoveringuy »

maxo-tt1 wrote:, you're right. but in signal pin comes 12v, where ms sends low volt signal... and this voltage goes in MS3x coil pins... thats why i think that there is not everything ok...

and when i check injector, in both wire comes 12v... from signal as well... :cry:

here on img 3 coil pin, where ms should send signal, but on this pins comes voltage (with stock bmw confiuration... i've changed nothing... just switched off ECU and tested pins with multimeter)
You need to be careful how you measure things...

If you have +12v feeding one wire of an injector, and you measure the voltage on the other wire while it's not connected to anything else, you will read +12v (even though that's where the injector gets grounded).

With no current flowing through the injector/coil/whatever the voltage is equal at all points.
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

hoveringuy wrote:
maxo-tt1 wrote:, you're right. but in signal pin comes 12v, where ms sends low volt signal... and this voltage goes in MS3x coil pins... thats why i think that there is not everything ok...

and when i check injector, in both wire comes 12v... from signal as well... :cry:

here on img 3 coil pin, where ms should send signal, but on this pins comes voltage (with stock bmw confiuration... i've changed nothing... just switched off ECU and tested pins with multimeter)
You need to be careful how you measure things...

If you have +12v feeding one wire of an injector, and you measure the voltage on the other wire while it's not connected to anything else, you will read +12v (even though that's where the injector gets grounded).

With no current flowing through the injector/coil/whatever the voltage is equal at all points.
oho.. very useful post. thanks... i'll check tomorrow again...

i feel that i have very little problem but cant catch it... everything looks to be ok... got signal from all sensors in tunerstudio... when i try to start engine, it writes in green cranked, synced and something else.. no errors in red... but engine not starts :( i think its coils... because injector flows fuel...
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

can someone tell me how to test coil driver with multimeter? i've removed it from stock siemens ecu.. and maybe it not works as bosch one?

i've done coil wiring according this
Image

maybe siemens needs wiring done differently?
hoveringuy
Experienced MS/Extra'er
Posts: 172
Joined: Fri Aug 29, 2008 8:52 am

Re: Megasquirt ON BMW m52 Engine

Post by hoveringuy »

maxo-tt1 wrote:can someone tell me how to test coil driver with multimeter? i've removed it from stock siemens ecu.. and maybe it not works as bosch one?



maybe siemens needs wiring done differently?
Can't just be tested with a multimeter. You'll need to connect the pin on the right to a ground, then use the the middle pin to sink a load. (12v light bulb, for instance). Bulb should light when +5v is applied to the left pin.
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

hoveringuy wrote:
maxo-tt1 wrote:can someone tell me how to test coil driver with multimeter? i've removed it from stock siemens ecu.. and maybe it not works as bosch one?



maybe siemens needs wiring done differently?
Can't just be tested with a multimeter. You'll need to connect the pin on the right to a ground, then use the the middle pin to sink a load. (12v light bulb, for instance). Bulb should light when +5v is applied to the left pin.
thanks.. i'll test it asap.

one more question please

as i noticed today, injectors doesn't flow fuel as well :( when i open ignition switch, 1 and 3(or 4) injector flows for a second and then stops... as stock ecu does... it seems to be normal... but not when i try tu start engine...

may incorrect cam sensor be the reason of this problem? (that injectors doesn't flow?) i've bought bosch one, but not sure it m50 or m44 cam...

and i use your msq file on alpha 18... with no changes... it seems everything is same in m54 and m52... how do you think?

i use sequential injection

please someone tell which are main sensors, that are must for correct fuel flow? no signal goes from ecu to injectors...
i ask it to double check wiring...

and one moer question.

bosch hall cam senor needs +12v or 5v?
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

hoveringuy wrote:
maxo-tt1 wrote:can someone tell me how to test coil driver with multimeter? i've removed it from stock siemens ecu.. and maybe it not works as bosch one?



maybe siemens needs wiring done differently?
Can't just be tested with a multimeter. You'll need to connect the pin on the right to a ground, then use the the middle pin to sink a load. (12v light bulb, for instance). Bulb should light when +5v is applied to the left pin.
i've just tried it... bulb not lights :(
protomor
Experienced MS/Extra'er
Posts: 367
Joined: Wed Feb 28, 2007 7:13 pm

Re: Megasquirt ON BMW m52 Engine

Post by protomor »

I just bought 2 of the DIYAutotune.com spark boxes. Means you have 2 spare if they ever break lol.
-Yoshi-
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

protomor wrote:I just bought 2 of the DIYAutotune.com spark boxes. Means you have 2 spare if they ever break lol.
sorry but what's spark box? :) link please
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

maxo-tt1 wrote:
hoveringuy wrote:
maxo-tt1 wrote:can someone tell me how to test coil driver with multimeter? i've removed it from stock siemens ecu.. and maybe it not works as bosch one?



maybe siemens needs wiring done differently?
Can't just be tested with a multimeter. You'll need to connect the pin on the right to a ground, then use the the middle pin to sink a load. (12v light bulb, for instance). Bulb should light when +5v is applied to the left pin.
i've just tried it... bulb not lights :(
oops.. my bad... i've done wiring wrongly at first time...

now it lights... so drivers are ok.... but engine still not starts...

can someone look at my log please?


p.s
can someone help me troubleshoot the problem? i'll pay 100-200$ for it...
protomor
Experienced MS/Extra'er
Posts: 367
Joined: Wed Feb 28, 2007 7:13 pm

Re: Megasquirt ON BMW m52 Engine

Post by protomor »

http://www.diyautotune.com/catalog/quad ... p-481.html

that's the spark box.

I'll look at the log when I get a chance at home.
-Yoshi-
maxo-tt1
Helpful MS/Extra'er
Posts: 142
Joined: Wed Dec 21, 2011 1:27 pm

Re: Megasquirt ON BMW m52 Engine

Post by maxo-tt1 »

protomor wrote:http://www.diyautotune.com/catalog/quad ... p-481.html

that's the spark box.

I'll look at the log when I get a chance at home.
i think i don't need this box :)

please someone look at my log :cry:
protomor
Experienced MS/Extra'er
Posts: 367
Joined: Wed Feb 28, 2007 7:13 pm

Re: Megasquirt ON BMW m52 Engine

Post by protomor »

There's no RPM signal in this datalog. Can you spit out a composite log and trigger log for me?

edit: too lazy to look back.Do you have the 10k resistor in line with your crank signal? If not, it's def needed.
-Yoshi-
Post Reply