RomRaider

For most temp sensors, if you disconnect them, they read their coldest possible. So by doing so you forced the ECU to use more fuel during cranking. And if you left it off while the engine was running the ECU was thinking the coolant was about -40C

About the MS40, it seems like certain engines got a Bosch ECU while others got a Siemens ECU. So you're both right.
It looks like the MS40.0 couldn't control VANOS but the MS40.1 could.

It looks like the main connector is the same. Have you looked into swapping in a newer MS41 ecu for ease of tuning?

Does your chip just pop out or do you desolder it?

From MS40.1 to MS41.x seems need to change the engine wiring aswell.
I changed mine from MS40.1 to MS41.1 with engine wiring. Since my car with automatic transmission I changed the EGS ECU as well. But some issue on speed sensor and kickdown not working. still need to find out the wiring connection to body wiring

It came with a socket already. So just pop it out and read it, buy some eeproms and start messing.
It's little tricky getting it out thought and I can only fit one finger in there to insert it again.
I'm always worried I'll break something.
The DME consists of two boards. The chip is right in betwean them. Sandwiched :p

I really wanted to change to my MS41.1 I got in my other E36. But never found out if I could just swap em. That one I just read with my KWP2000+ and was out tuning with my laptop. Was much more nicer experience :p
I guess the MS41.1 have no problem running the m50b20vanos engine. Just the wiring need to match.
The MS40.1 only have 1 lambda and not two (one for each banks) like the MS41.1.

About the coldstart. This morning again same problem. Got under the hood disconnected the sensor and the car started and idled perfectly like the engine was warm. So I might just add a switch for the temp sensor. We'll see when it gets even colder.

So you think I'm too lean when coldstarting with the sensor connected, right?

The MS41 can be flashed to be just one lambda



And then if you don't want control of the post cat, you can get that disabled as well.

There are even factory MS41 ecu flashes that run M52B20 engines pretty much like your M50, of course you'd have to wire it all.

http://prodcds.bmwuniversity.com/librar ... MS41-2.pdf

About my starting problem and why my car starts first crank when I disconnect the sensor:
"If the Coolant Temperature Sensor input is faulty, a fault
code will be set the ECM will assume a substitute value
(80º C) to maintain engine operation."

My guess that I was running way to rich when cold cranking is correct I suppose. Gonna try to alter that coldstart map and see what happens .
Anyone here know how the tempeture axis relates to actual degrees in Celcius? I mean what is the lowest and what would in my case (8bit 1x8 Map) 255 as maxium point to? So I have a guess where to begin.

Interesting about the default temp if failure, that is a good idea. For the MS41.2 it is x*.75-48 to convert from volts to deg C.

For those more advanced than me. Please help me find the MAF-table.
And enrichment maps. I've found so many maps in wols but can't figure out what is what.

After finding out that the two 16-bit words before the maps are pointers to their axises it wasn't that hard to find alot of the smaller more harder to see maps. MS40.1 usually have 8-bit axises so you know.

Here is my bin. And wols for the maps I found. Fuel Ingnition I have both WOT and P/T and I guess there are Vanos modifier maps.

Why I need your help. The throttle response is so s*** with my biggest MAF (3.5 inch). I can make the throttle response like I want it by modifying the fuel map with almost double the injection time. But then ofc the car is undriveable under normal conditions.
If I have good stable 14.7 crusing AFRs (the standard fuelmap adjusted for my injectors) the reponse is s***, but I can rev it slowly and have good AFRs.

This enrichment during throttle and MAF tabel is what I'm looking for.

The MAF-table I thought is the MAF-table don't change nothing. Can someone more experienced tell me what that 1x256 Map I thought is the MAF-table is?

And to clarify with fuel table for good AFRs the throttle response is normal without the MAF connected. But is slow and misfiring with the 3.5 MAF connected. (Slow revving = no misfires and good AFRs.)

After some extensive trial and error testing, changing one map at a time I found a 4x4 Map that affected enrichment on throttle.
The map is a 4x4 8bit at 0xD776.
Now I got a really fast, much better than stock response. Before I had an delay and the revs could even drop before anything happened.

so you not need help now? what tables you interested in now?

I would like to understand how the MAF/Load work.
I can't really scale for my 3.5 MAF and I have to adjust in the global fuel map.
The ignition gets affected and drivability is probably affected for the worse.

There is a 1x256 16bit MAP same size as the MS41.X but the values are not even close. And changing this one, even replacing it with a MS41 one doesn't affect anything from what I've noticed.

Stock MAF vs the 3.5 MAF differ around 20% in AFR holding steady at 2500 RPM.
Would be sweet if I could scale the MAF properly.

Load = MAF / RPM

If you believe there is a 20% difference in MAF then for bigger MAF, multiply your Fuel and Timing Load Axis by 0.8 if you are not modifying the MAF scaling.

This approach beats adjusting the fuel map. Thanks, I feel stupid that I haven't tried it. :p