1 Fuel Pump has no power - lost Sun Nov 22, 2020 4:11 pm
dallasf
Silver member
Hi,
So I am very new to the world of the BMW K's and motorbikes in general (technically). Have always ridden and enjoyed bikes but never really pushed myself to learn what is "underneath".
I searched for quite a long time to find the right bike and came across a beaten up k100 RS SE 1989. It had been stored in a garage for about 4 years and looked like it has potentially been dropped, with only minor damage. The bike is a non-starter and that's kind of what I wanted to really learn.
Please excuse the below information it may seem incorrect as it may well be. I tried to follow the guides and forum posts best I could. The overall issue I have is that the fuel pump is not getting any power. I have checked the following:
New Battery
Bike is on the center stand - side stand is up
Bike is in neutral
Bike cranks no problem with ignition on, no key as key lock was jammed. I juts use a screw driver to turn it on.
Cleaned grounding points – were filthy
Removed fuel pump and connected 12v and had a steady stream of fuel. This did not occur whilst in the tank.
Replaced fuel filter
Water temp light is NOT on
12v multimeter test connection at the fuel plug which connects to the tank on all 4 pins when starter active, I hear this can be the cause – reads:
White 7.9
Yellow 7.4
Brown .23
Green 10.26
Tested wires from fuel pump connection to external pin connection, no issues, no wires broken.
All fuses are tested and working
Fuel Pump relay tested, can hear it open and shut with 12v, check via multimeter and appears to be working fine.
FI Relay - Put the red lead of my tester on pin 30 of the socket and the black one to a good ground - all clear
FI Relay - Put the red lead of your tester on pin # 86 and the black one to a good ground. When I turn the ignition key ON I was reading 12v on the meter.
FI Relay - Put the red lead of the tester to the positive (+) of the battery and the black lead to pin # 85 of the socket. When I press the starter button read 12v on voltmeter. IT READS ABOUT +10.9
Next step is to check the power from the relay to fuse #6 (I apply 12v to test the pump. To do so, I reconnect the relay. Got a good ground on the black lead voltmeter and when pressing the starter button, touch each side of the fuse with the red lead. Worked with 12v
Power from ECU connector to FI relay 85 registers nothing but 86 reads 12v - might be the cause?
I placed the multimeter (12v) on pin 12 of the EFI connector and then to the injector, which returned no results, thoughts??
Remove the FI relay again and got the voltage at pin #30 of the socket - All fine, correct voltage.
Got an LED and attached the LED to the injector and started the bike, this starting flashing at me. I hear if the injectors don't start the pump won't.
Guys I am lost, I have read the flow diagram but I am really scratching my head as I do not really under the instructions all that well.
I do apologise if the above seems not "technically" correct.
Your help is much appreciated.
Thanks, Dallas
So I am very new to the world of the BMW K's and motorbikes in general (technically). Have always ridden and enjoyed bikes but never really pushed myself to learn what is "underneath".
I searched for quite a long time to find the right bike and came across a beaten up k100 RS SE 1989. It had been stored in a garage for about 4 years and looked like it has potentially been dropped, with only minor damage. The bike is a non-starter and that's kind of what I wanted to really learn.
Please excuse the below information it may seem incorrect as it may well be. I tried to follow the guides and forum posts best I could. The overall issue I have is that the fuel pump is not getting any power. I have checked the following:
New Battery
Bike is on the center stand - side stand is up
Bike is in neutral
Bike cranks no problem with ignition on, no key as key lock was jammed. I juts use a screw driver to turn it on.
Cleaned grounding points – were filthy
Removed fuel pump and connected 12v and had a steady stream of fuel. This did not occur whilst in the tank.
Replaced fuel filter
Water temp light is NOT on
12v multimeter test connection at the fuel plug which connects to the tank on all 4 pins when starter active, I hear this can be the cause – reads:
White 7.9
Yellow 7.4
Brown .23
Green 10.26
Tested wires from fuel pump connection to external pin connection, no issues, no wires broken.
All fuses are tested and working
Fuel Pump relay tested, can hear it open and shut with 12v, check via multimeter and appears to be working fine.
FI Relay - Put the red lead of my tester on pin 30 of the socket and the black one to a good ground - all clear
FI Relay - Put the red lead of your tester on pin # 86 and the black one to a good ground. When I turn the ignition key ON I was reading 12v on the meter.
FI Relay - Put the red lead of the tester to the positive (+) of the battery and the black lead to pin # 85 of the socket. When I press the starter button read 12v on voltmeter. IT READS ABOUT +10.9
Next step is to check the power from the relay to fuse #6 (I apply 12v to test the pump. To do so, I reconnect the relay. Got a good ground on the black lead voltmeter and when pressing the starter button, touch each side of the fuse with the red lead. Worked with 12v
Power from ECU connector to FI relay 85 registers nothing but 86 reads 12v - might be the cause?
I placed the multimeter (12v) on pin 12 of the EFI connector and then to the injector, which returned no results, thoughts??
Remove the FI relay again and got the voltage at pin #30 of the socket - All fine, correct voltage.
Got an LED and attached the LED to the injector and started the bike, this starting flashing at me. I hear if the injectors don't start the pump won't.
Guys I am lost, I have read the flow diagram but I am really scratching my head as I do not really under the instructions all that well.
I do apologise if the above seems not "technically" correct.
Your help is much appreciated.
Thanks, Dallas
Last edited by dallasf on Sun Nov 22, 2020 10:28 pm; edited 3 times in total