L jet info - running rich
Posted: Wed Feb 06, 2019 5:45 am
found this today
http://www.injectronics.com.au/assets/Uploads/T0067.pdf
" Document number: T0067
TECHNICAL BULLETIN
For further technical information regarding testing, repairs or to search for New or Remanufactured Automotive electronic products, please visit www.injectronics.com.au, call our office on (+613) 8792 6999, or email sales@injectronics.com.au
Make: BMW
Model: 5 & 7 series, early to mid 80’s Subject: Running rich
Some early to mid 1980 BMW 6 cylinder engines used the Bosch L Jetronic system. This was the earliest of the air flap type engine management systems and used a 35 pin ECM.
The ECM pin 4 monitors crank signal from the starter motor and uses this signal to give start up enrichment. There should be zero volts at this pin when the engine is running or the key is just in the on position. When cranking there should be a crank voltage of approx 10 volts depending on the voltage drop.
Injectronics has had many customers call to say they have a running rich BMW and upon questioning we have learnt that starter motor work has been performed. In some cases a relay has been wired into the starter circuit, which causes a voltage to be present on pin 4 when the engine is running. This of course will make the engine run rich. To confirm this is your fault check the voltage at pin 4 with the engine running and it should be zero volts. If there is a voltage present, disconnect the relay or temporarily cut the wire going to pin 4.
T0067.doc
This publication is distributed with the understanding that the authors, editors and publishers are not responsible for the results of any actions or works of whatsoever kind undertaken on the basis of information contained in this publication, nor for any errors or omissions contained herein. The publishers, authors and editors expressly disclaim all and any liability to any person whomsoever whether a purchaser of this publication or not in respect of anything and of the consequences of anything done or omitted to be done by any such persons in reliance, whether whole or partial upon the whole or any part of the contents of this publication. Injectronics Australia Pty Ltd. © Copyright 2001.
http://www.injectronics.com.au/assets/Uploads/T0067.pdf
" Document number: T0067
TECHNICAL BULLETIN
For further technical information regarding testing, repairs or to search for New or Remanufactured Automotive electronic products, please visit www.injectronics.com.au, call our office on (+613) 8792 6999, or email sales@injectronics.com.au
Make: BMW
Model: 5 & 7 series, early to mid 80’s Subject: Running rich
Some early to mid 1980 BMW 6 cylinder engines used the Bosch L Jetronic system. This was the earliest of the air flap type engine management systems and used a 35 pin ECM.
The ECM pin 4 monitors crank signal from the starter motor and uses this signal to give start up enrichment. There should be zero volts at this pin when the engine is running or the key is just in the on position. When cranking there should be a crank voltage of approx 10 volts depending on the voltage drop.
Injectronics has had many customers call to say they have a running rich BMW and upon questioning we have learnt that starter motor work has been performed. In some cases a relay has been wired into the starter circuit, which causes a voltage to be present on pin 4 when the engine is running. This of course will make the engine run rich. To confirm this is your fault check the voltage at pin 4 with the engine running and it should be zero volts. If there is a voltage present, disconnect the relay or temporarily cut the wire going to pin 4.
T0067.doc
This publication is distributed with the understanding that the authors, editors and publishers are not responsible for the results of any actions or works of whatsoever kind undertaken on the basis of information contained in this publication, nor for any errors or omissions contained herein. The publishers, authors and editors expressly disclaim all and any liability to any person whomsoever whether a purchaser of this publication or not in respect of anything and of the consequences of anything done or omitted to be done by any such persons in reliance, whether whole or partial upon the whole or any part of the contents of this publication. Injectronics Australia Pty Ltd. © Copyright 2001.