Megasquirt Support Forum (MSEXTRA)

Hi! I am new in this field. I got bmw with m50b26 almost stock engine for some time I have been working on getting my car to start (with ms2 v3.0 board). The problem is that I have no fuel(fuel relay not working) or spark(checked with coil and spark plug to GND). I have RMP signal while cranking, and the LEDs are flashing on MS2 when its cranking. All the gauges are working like TPS,Temps etc.(egine temp gauge is bad,showing 51C), When I turn the ignition key on a see ECU relay coming alive but so I assume that relay circuit is working properly. Any ideas what have been a missed? Is this can be a setting/software problem, or bad wiring? The interesting thing is that when a connect ms2 to car with the ignition key on fuel pumps starts for 2 sec. When the ignition key is on getting +12V on pin 37. My realy circuit is switching ground. I read somewhere that i need to get 5V on R19 if ecu is sendig signal. Iam getting +12V there. Struggling for while with this small fancy thing. Thank you in advance!

https://www.youtube.com/watch?v=8Jh7fSJPzdI
https://www.youtube.com/watch?v=pyJXTtfZw0M

have you got an additional coil drivers mounted somewhere i cant see? same goes for a 3rd injector driver?

The MS2 card does not have the modifications needed for the additional drivers and you're not set to run semi-sequential injection. So don't have it set to use the additional drivers in the engine and sequential settings; set it for the standard drivers.

Jean

grom_e30 wrote:have you got an additional coil drivers mounted somewhere i cant see? same goes for a 3rd injector driver?

Yes,I am using original bmw coil transistors mounted on adapter harness. I found out that there are some project running with stock (ECU) transistors. The only difference is that I am using 100ohm resistor on each transistor(base pin) and one 1K resistor in signal line. Its 1200ohm on one spark output double as much as the manual says for vb921 (660ohms).Mybe problem lays there too? I am using BU323Z ignition trasistors by the way and they ar connected in pairs spark A goes to cyl 1&6 B goes to 2&5 and C goes to 3&4.
https://www.onsemi.com/pub/Collateral/BU323Z-D.PDF


Thanks Jean for so quick response. So if i change the settings it will turn ground on pin 37? Because as I said, right now a have +12V going out from pin 37 but looking at the manual(schematic) it should ground the pin 85 on the relay. Sorry for stupid questions am far from electronics
Thank you in advance.
Martin.

the ecu should ground the fuel pump output, are you measuring the 12v on the fp with the ecu connected to the car? as its prob the voltage from the relay you are measuring

I am measuring with my multemeter +12V on pin 37 to ground so I assume that the pin 37 is positive but i will double check that tomorrow.
I have home made relay control circuit built in ms V3.0 proto area with 2N2222A transistor and it works like that--the base is connected with car ignition key and 2N2222a trasistor swithes ground to pin 4 on DB37. Then the signal(let's call it like that)goes to car adapter harness pin 27. When i turn on ign key the ecu relay clicks (and as i disassemble the relay case) and see that ECU relay is working. The interesting thing is that when I disconnect and then connect back to the ECU with ign key on fuel pump comes alive for 2sec or so.

I will check if there is a power to injectors to be sure that ECU relay is working properly(in attached shematic we can see ecu relay pin 87 turning on all injectors) but I think there is no problem with that. In the beginning i had a problem that i was turning on relays with +12V (2n2222a transistor emitter was connected to +12V),nothing worked then. I quickly found out my mistake. Maybe in that step i burned down something in MS2 board? (but that will be nonsense because only think I am using on v3.0 board was +12v from u5 and proto area). When a disconnect MS2 and connect back the stock ecu car starts right away idle is a little bit rought but thats because there is no exhaust and no O2 sensor.
And I had some power problems (my mistake with car battery booster) where C16 capacitator died but everything else survived, and i got burn trases in board where the C16 connect to D10 (if I am correct) maybe then something happened because that was first time i connected MS2 to car. Then there was no power to ecu relay and when the C16 capacitator blew up i notice my mistake with relay circuit. But that was like with in 10min.
Thank you in advance and sorry for bad writing. Not my native language.
P.s. D37 pin 37 is connected to cars adapter harness pin 1

форсунка-injector
реле топливный насос-fuel pump relay
реле ECM-ECU relay

Is there some confusion here? With the standard hardware configuration, the mainboard DB37 pin 37 can only "ground" an external load; it will either be at near-zero volts or floating when no load is connected. You can never get 12V from that pin 37 alone, regardless of any settings in TS.

Thank you. I will double check that. Maybe i am just daydreaming about that.
What you think about ign transistor resistance? Is it too much?

You are asking about the 1200 ohm series resistor in the base circuit of BU323Z? Yes, I think that is too much for optimum/reliable use in driving an ignition coil.

Hi. Thank you for helping. I don't know how but the fuel pump issue solved out by itself. When I found out that there is a test mode section in tuner studio. Tested the fuel pump and every think started to work(fuel pump). Changed resistors for ignition transistors to 600ohm and now I got spark too.

But there is another problem with the fuel supply sistem. There is no injectors firing when a set to semisequential and when I set it to untimed injection only bank2 to is firing. I ran diyautotune trouble shooting and found out that both injector lights so a assume that the board is fine. The wiring is one on one i triple checked that there is no faults.
It can be a software issue?(I read it on this forum) Or once a gain i have two left arms
Again with stock ecu, plug that and car starts right away.

Hm I will try to attach datalogs and current tune(sorry, the board attachment quota has been reached)
P.s. datalog is with untimed injection car want to start but can't because only 3 injectors is firing and i think ignition is a little bit off too. Second is with semisequential and third is again whith untimed.
Thank you all in advance.
Again sorry about bad english

https://drive.google.com/drive/folders/ ... sp=sharing


I hope this works.

you cant run semi sequential on a 6 cylinder with only 2 injector drivers.

do both banks fire in injector test mode?

Hi everyone. Wound out my mistake and started the car
The mistake was if you look in third attached picture you can see that there is some parts missing, especially R37. Again my bad.

Thank you all for support.