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-   -   1991 850i eml light (http://www.bimmerfest.com/forums/showthread.php?t=626716)

wharpermd 06-12-2012 01:35 PM

1991 850i eml light
 
sometimes my 1991 850i will crank and run rough when the eml light stays on. cut it off and recrank until eml light stays off and runs smooth as silk. someone said something about throttle position sensor. does anyone know or have advice?

TxGr8White 06-12-2012 02:19 PM

DK motors are probably needing a refurb - common problem with these cars.

wharpermd 06-15-2012 02:01 PM

do you know anything about throttle position sensor?

TxGr8White 06-15-2012 03:49 PM

There is really no such thing by itself. The throttle positon is determined by the wiper arm within the DK motors. They send back signal voltage to the individual DME's which in turn is interpreted by the EML. The EML makes sure that both "halves" of the engine are in sync with each other. The EML light can indicate that one side of the motor is not keeping up with the other. This can be a number of things:
- DK motor getting hung up, or sticking
- O2 Sensor failure
- DME failure
- Fuel pump failure on that side
- Distributor cap/rotor faulty
- MAF faulty
- Intake gasket leak
- FPR failure
- CPS failure
- Impulse sender failure

As you can see, you will first need to try and narrow it down. Which side of the motor is not running? You can tell by which exhaust is cooler than the other after a few minutes of running. Also note that from the front of the car where the air enetrs each side until you get to the individual head, the left side feeds the right and vice versa. Once the air/fuel is in the head, then left is left and right is right. In other words, if your drivers side exhaust is cold, then you might have MAF, DK motor, or intake gasket probl;ems on the right side of the engine.

Let us know what you find.

Good luck

wharpermd 06-21-2012 10:12 AM

DK motors 850i
 
does the intermittency of the problem mean anything to you? usually after it cranks and runs smoothly, it does not happen again that day no matter how many times you crank it.

Retired777 07-07-2016 10:09 AM

E31 M70 EML Synchronizing
 
Good morning E31's

I have been working on my 850i and disconnected the batteries.
The batteries were disconnected for 1 week; I have been told that now the EML's will need to be synchronized as they would have 'lost their memory'.... any ideas how to re-sync. the units?

Thanks
Eric


Keep the shiny side up:thumbup:

adwebinc 07-14-2016 03:27 PM

Quote:

Originally Posted by Retired777 (Post 9749193)
Good morning E31's

I have been working on my 850i and disconnected the batteries.
The batteries were disconnected for 1 week; I have been told that now the EML's will need to be synchronized as they would have 'lost their memory'.... any ideas how to re-sync. the units?

Thanks
Eric


Keep the shiny side up:thumbup:

Sorry... the e31 board here is not frequented often. The bimmer forums board has a specialty group for e31s.

Are you talking about synchronizing your DK motors? If so, most people say that you can just drive the car around like normal and they will ultimately adjust. There is a specific DK sync process (do a google search for that) that I have tried, but I didn't notice any particular difference from just driving the car around.

Retired777 07-15-2016 10:12 AM

Hi adwebinc

Thank's for the reply...

I have also been told that just driving around normally would re-synch the DK's and the EML's.

After I replaced all the hydraulic lifters, stripped down and did a major clean of the DK motor's and throttle bodies, this is what I did:

I found a process that appears to be from some kind of service manual in which you need to: "'Start the car, let engine idle up to operating temperature, then select 1st gear and gradually drive up to about 5500-6000 rpm (just below redlining) then let the car coast down to idle... repeat again a couple of times". I did this on a long quiet country road. The car now drives very smoothly and is very responsive. I don't know if this is due to the above process or what...but I thought I would share it with the E31 brigade.

Now I would like to find a program that I can use on my laptop that will 'talk' to the 850 V12 and not just code read. Any suggestion's?




Keep the shiny side up :thumbup:

adwebinc 07-15-2016 08:38 PM

1991 850i eml light
 
Quote:

Originally Posted by Retired777 (Post 9760114)
Hi adwebinc

Thank's for the reply...

I have also been told that just driving around normally would re-synch the DK's and the EML's.

After I replaced all the hydraulic lifters, stripped down and did a major clean of the DK motor's and throttle bodies, this is what I did:

I found a process that appears to be from some kind of service manual in which you need to: "'Start the car, let engine idle up to operating temperature, then select 1st gear and gradually drive up to about 5500-6000 rpm (just below redlining) then let the car coast down to idle... repeat again a couple of times". I did this on a long quiet country road. The car now drives very smoothly and is very responsive. I don't know if this is due to the above process or what...but I thought I would share it with the E31 brigade.

Now I would like to find a program that I can use on my laptop that will 'talk' to the 850 V12 and not just code read. Any suggestion's?




Keep the shiny side up :thumbup:



Yes, that's it! That is the "official" DK sync process. So sounds like it worked for you.

There is a process you can use to add the INPA and dis official BMW software to a laptop to read and code the 850 DMEs and EML. However, the best performing set up is an older Dell or IBM with an actual serial port and dedicated to just the diagnostics to avoid software conflicts. You will also need the special 20 pin diagnostic head of course. I bought mine prebuilt off eBay for a couple hundred bucks, but many have success building it themselves.

I also saw a referral to this set up yesterday (have to find link).

Here it is - http://www.bcables.com


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Wuffer 07-16-2016 11:34 AM

Where in Canada? If in BC, I have BMW Diagnostic Software on a laptop in Langley and would be happy to assist. Visit www.wuffer.ca
Cheers,
Tom
wuffer at shaw dot ca

Retired777 07-26-2016 11:51 PM

Hi ADWEBINC and WUFFER,

I also have an old laptop but it does not have a serial (RS232) port. A few years ago I purchased an interface which has the 20 pin BMR adapter that is connected to a box of electronics which has the serial cable. I also have a 20 pin to OBD2. This all came with CARSOFT V6.5. As my old laptop does not have the RS232 I never did get a chance to use the unit so don't even know if it will talk to the 850!!

The software 'how to manual' suggests I use a PCMCIA to serial adapter and not serial to USB as this would not work. Now...has anyone out there had any success with the USB adapter and CARSOFT or even using the 20 pin to OBD2...does the OBD2 reader able to talk to the 850 or does it use a different protocol?

Soooo many questions??

BTW Wuffer..its me.. the Princeton guy with a red 850 that has the steering wheel ...on the other side!?


Keep the shiny side up :)


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