I just swapped an M52B28 into my 1987 325is. It's using a Red Label 413 DME which is 3.3.1 I believe. It has Pink top injectors and an M50 Manifold and I purchased a 1995-1996 BMW M3 MAF Part No. 13621747155. The chip that was in the DME when I bought the setup seemed to have been the stock M50 chip that would have been in that DME (I assume the PO yanked the performance chip since she was just rich at idle and lumpy when I started her the first time). I rescaled the injector values to match the Pink Top injectors and the idle smoothed out beautifully... however... only when the MAF is unplugged (Alpha N). Once the MAF is plugged in it goes back to a surging idle and smells rich (I wish I added my wideband when I welded the exhaust but I didn't unfortunately). I scaled the MAF table down by using a multiplier of .8 and it idled a bit better but eventually stalled. Would anyone happen to know what the MAF table should be for this particular MAF?
I have also compared my MAF Cal kg/h table against a public base OEM bin for 95 e34 525i Manual with an M50 and they match so from that perspective they are valid however I know that is based on that particular setup and not mine.
Not sure whether this is one of those things that you really need a wide band and your particulars in order to figure it out... or whether someone has something that might get me in the ballpark because I know this type of setup was done many times before.
EDIT... I just looked and the MAF I purchased is the one for a 95 e34 525i... so I dont' get why she is not happy with it.
Final EDIT mods can delete this. I Reverted back to my original BIN and somehow all things are fine now and this MAF is the correct MAF for my Base BIN settings. Apologies for the confusion.
NEWB Help 3.3.1 MAF Tuning cant get this right M52B28 swap into E30
Moderators: robertisaar, dex
Re: NEWB Help 3.3.1 MAF Tuning cant get this right M52B28 swap into E30
I used the OE 95 525i BIN and the setup should be perfect for the MAF and injectors. Issue I have now is when returning from higher revs back to an idle it loops 3-4 times and then settles in. I noticed that when my wife went to roll down the window at a steady idle it seems to bump into that loop again so I just re-ran another ground cable to the engine to see if that helps. Seems like when I leave her in gear and decel I can hear when decel kicks in and she doesn't loop at idle... however when I just pop the clutch from higher RPM's she loops at idle. Not sure if this has anything to do with a table setting but please suggest if you have any ideas. Thanks in advance.
Re: NEWB Help 3.3.1 MAF Tuning cant get this right M52B28 swap into E30
Glad you got it figured out.
It was hard to tell what you were doing as far as changes to the tune. I read like you were making changes that you should not. Injector scaling you mentioned sounded sketch. If you attempted to just change the injector scale value and nothing else...that does not work, we all wish it worked like that but that is not how it works in this DME/ECU. Now there are 2 tables in the OEM tunes that are essentially unused and can be used for small injector size corrections as long as a few things are not violated.
There is a lot of material to read about how to tune these cars. There is also a lot of misinformation noise on the web also which is why I named my thread like it did.
Regarding the MAF calibration data in the rom. The MAF calibration data is matched to MAF versions. The MAF calibration should not be edited. If you swap to a different version MAF the MAF calibration for the new MAF is to be copy pasted in. There are also other MAF related values that should be copied in when doin a part swap.
YES you can affect the tune by manipulation of the MAF calibration BUT you should not. Editing the MAF calibration is getting the system to lie about how much mass air flow is entering the engine.
Tuning should be done in the tuning tables.
ugh.... but.... if someone makes a custom MAF or buys a sensor and puts it in a tube then the Calibration for that MAF has to be custom made. Sensors come with tools to generate the data. The rule here is only edit Calibration data if you are working with an unknown MAF. If the MAF has a known calibration data set from the factory use only the factory calibration. Then, tune the car with the tuning tables.
all these ifs ands or buts have lead to a lot of scenarios of great misunderstanding.
It was hard to tell what you were doing as far as changes to the tune. I read like you were making changes that you should not. Injector scaling you mentioned sounded sketch. If you attempted to just change the injector scale value and nothing else...that does not work, we all wish it worked like that but that is not how it works in this DME/ECU. Now there are 2 tables in the OEM tunes that are essentially unused and can be used for small injector size corrections as long as a few things are not violated.
There is a lot of material to read about how to tune these cars. There is also a lot of misinformation noise on the web also which is why I named my thread like it did.
Regarding the MAF calibration data in the rom. The MAF calibration data is matched to MAF versions. The MAF calibration should not be edited. If you swap to a different version MAF the MAF calibration for the new MAF is to be copy pasted in. There are also other MAF related values that should be copied in when doin a part swap.
YES you can affect the tune by manipulation of the MAF calibration BUT you should not. Editing the MAF calibration is getting the system to lie about how much mass air flow is entering the engine.
Tuning should be done in the tuning tables.
ugh.... but.... if someone makes a custom MAF or buys a sensor and puts it in a tube then the Calibration for that MAF has to be custom made. Sensors come with tools to generate the data. The rule here is only edit Calibration data if you are working with an unknown MAF. If the MAF has a known calibration data set from the factory use only the factory calibration. Then, tune the car with the tuning tables.
all these ifs ands or buts have lead to a lot of scenarios of great misunderstanding.