Author Topic: Help Needed with M50B25 (BMW E36 325) fueling setup  (Read 11248 times)

Offline jtoro

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Help Needed with M50B25 (BMW E36 325) fueling setup
« on: April 17, 2012, 01:15:12 am »
Hello, I am Juan from Colombia.

My project car is a 1995 Euro version BMW 325 (E36). I am aiming for a fast daily driver around 300 – 350 whp on it’s first stage. For this, I will be using a VEMS 3.6, and a T04E turbo. I am a complete newb on standalones, turbos etc. but I have read everything I have been able to find about this.

My first step is getting the car to run with the Vems, on a stock engine. This way I get to learn without risking the engine. My Vems was bought to Vems USA and wsa configured with 8 high current outputs, secondary trigger and internal MAP.
The cable splicing – connections was relatively simple thanks to Phat Bob’s tutorial and some Haynes manuals I had with the wiring diagrams of the car. I set everything in paralell so I can still use the oem ECU (comes handy when you drain the battery, flood the engine or need to get it warmed up to make it easier to start).
I followed instructions on the VEMS website, and the calibration guides on this forum and who knows what more.
This brings me to the point where I can start the engine and get it to idle around 600 rpm by tricking VEMS setting crank speed at 1000 rpm because the car stalls as soon as it goes over the cranking threshold.
My setup is using wasted spark with oem COP and injectors are fired simultaneously during cranking and secuentially during running.

The problem is that the engine will not hold idle on running mode, it has to be on cranking mode which fires all injectors at a time and will hold for a few minutes. I have set the cranking VE around 70 to get it running and manually lower it to 40 where the exhaust gases will not smell rich (wideband will not read during cranking). Spark advance is set to 10 degrees.
I have changed afterstart, cranking and warmup enrichments to 0 and spark table is set to the same 10 degrees of cranking and VE table is set to 40 in the idle sections of the map so there is no change on fueling or spark when the ECU changes from cranking to running mode. Despite all this, RPMs fall as soon as the Cranking flag changes to running.
I even changed the firmware to rule out bugs on that side, with absolutely no change.
I have tried everything I know of with no success and will apreciate any insight from the community.

These are some of the logs
http://dl.dropbox.com/u/22341976/v3.3_u004568-2012.04.15-12.50.18.vemslog
http://dl.dropbox.com/u/22341976/v3.3_u004568-2012.04.15-13.01.38.vemslog
http://dl.dropbox.com/u/22341976/v3.3_u004568-2012.04.15-13.17.23.vemslog

And the config file
http://dl.dropbox.com/u/22341976/5_sesostieneconve35Firmware1.1.80.vemscfg

Offline GintsK

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Re: Help Needed with M50B25 (BMW E36 325) fueling setup
« Reply #1 on: April 17, 2012, 03:09:46 pm »
Trigger log file would be helpful.

I suggest  to upgrade to released firmware instead of suspicious 1.1.80!
My recommendation is 1.1.95 or 1.1.96. It will give better triggerlog representation.

Use for that newest Vemstune and f/w upgrade will be pretty easy.

Are you sure about trigger angle and coil pairing/sequence? Else seems with no extreme errors at first look.

Gints

Offline jtoro

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Re: Help Needed with M50B25 (BMW E36 325) fueling setup
« Reply #2 on: April 17, 2012, 08:04:39 pm »
Thanks for your help. I had 1.1.95 but changed to this old one trying to rule out firmware issues.

Trigger log looks fine, I can't attach one right now but I counted the events by hand and everything is ok. As far as trigger angle, I have checked it with a timing light and is ok.

Coil Pairing:

I have wired each one to an output and paired 1 and 6, 5 and 2, and 3 and 4, but will double check.

Offline GintsK

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Re: Help Needed with M50B25 (BMW E36 325) fueling setup
« Reply #3 on: April 18, 2012, 05:51:24 am »
Injector size? Rail pressure?
What is wrong with your MAP sensor?
« Last Edit: April 18, 2012, 05:57:28 am by GintsK »

Offline jtoro

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Re: Help Needed with M50B25 (BMW E36 325) fueling setup
« Reply #4 on: April 22, 2012, 12:54:27 am »
I am using stock injectors, supposed to be 200cc. I haven't measured rail pressure but the car is running on the stock ECU so I ama assuming it is ok.

Offline GintsK

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Re: Help Needed with M50B25 (BMW E36 325) fueling setup
« Reply #5 on: April 22, 2012, 07:30:50 am »
Hm.
Then use VE values around 70-85 where you have 40.

And car runs better with fuel pump ON. Now seems your pump turns off...

Gints

Offline jtoro

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Re: Help Needed with M50B25 (BMW E36 325) fueling setup
« Reply #6 on: April 23, 2012, 02:37:51 am »
Your comment made me double check my setup and I found out a stupid mistake. I had + signal to the fuel pump. I inverted the output and everything started to work as expected. I was being able to run the engine for a while because of the leftover pressure in the fuel rail after using the OEM ECU.

Thanks a lot!!!!


Offline jtoro

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Re: Help Needed with M50B25 (BMW E36 325) fueling setup
« Reply #7 on: April 23, 2012, 02:38:54 am »

What is wrong with your MAP sensor?

I am at a place 2,300 meters above sea level, that is why max kPA is around 80 :)