1 1985 K100RS not running right Fri Jun 28, 2013 11:12 pm
KiltedK100
active member
Greetings,
I have a 1985 K100RS that is ailing. It has about 41,100 miles on it and had generally been reliable until one day. To be specific it ran fine one day, and I came home and parked it and the next morning this problem presented itself. It wasn't starting (it was turning over) and gas was dripping out of the union where the headers meet the tailpipe.
Here is what I have done:
Cleaned the electrical connections (not inside of the relay box recently)
I inspected the plugs and it seemed that cylinder #4 was flooding
My spark plug leads were replaced with a new set from Beemer Boneyard about 5,000 miles ago
I gapped and replaced the spark plugs
I visually confirmed that all plugs were sparking
I tested the ignition coils, mine were reading low (coil1/4 9.87k ohms at HT, and 2.9 at the leads. and 2/3 was 9.69k ohms at HT and 3 ohms at the leads). I ordered a used set to replace them. The used set came with 1 good coil and 1 bad coil. Swapping the good coil in resulted in it starting but not firing on all cylinders. I ordered two new OEM coils with orange towers and have installed them.
I measured the fuel pressure (36 pounds as expected)
I checked the resistance on the injectors they varied from 15.8-16.6 ohms
I checked that all the injector leads were pulsing with a 12V LED
I manged to find a set of 4 new injectors for cheaper than the cost of having mine cleaned. Installed them and though it still doesn't idle correctly there is no longer fuel pouring out of the union in the exhaust
I replaced the air filter
I replaced the fuel filter
I replaced all the fuel lines outside of the gas tank as they were old and cracking
I installed quick disconnects on my fuel lines that has made removing / installing my tank a lot more pleasurable
I replaced the alternator drive bushings
I replaced the coolant level hose
I replaced the Z engine breather hose (it was cracked and had foamy goop in it)
I checked for vacuum leaks with a propane cylinder
My battery is reading 13.23 volts
When I last started her up she wouldn't idle without me staying on the throttle and when I let off would pop and die. This seems to be the case whether the Throttle Position Switch is connected or not.
The plugs all look good and not flooded
I can rev the engine up to 8,000 RPM in neutral on the center stand with a bit of hesitation around 2,000 RPM and it seems ok
I placed a penny between the throttle body adjuster screw and stop and it seems to idle now.
When I take it for a test ride it feels like it has no power and isn't running like it was previous to the day when it decided to no longer start.
Could anyone suggest where I should go next before working my way through all the other items in the EFI/Electronic ignition K100 2v troubleshooting guide? I'm really hoping to make it the BMWMOA rally in Salem, but at this rate I don't know that I will. I only have two more paychecks before I need to leave. Thank you!
~Ryan
I have a 1985 K100RS that is ailing. It has about 41,100 miles on it and had generally been reliable until one day. To be specific it ran fine one day, and I came home and parked it and the next morning this problem presented itself. It wasn't starting (it was turning over) and gas was dripping out of the union where the headers meet the tailpipe.
Here is what I have done:
Cleaned the electrical connections (not inside of the relay box recently)
I inspected the plugs and it seemed that cylinder #4 was flooding
My spark plug leads were replaced with a new set from Beemer Boneyard about 5,000 miles ago
I gapped and replaced the spark plugs
I visually confirmed that all plugs were sparking
I tested the ignition coils, mine were reading low (coil1/4 9.87k ohms at HT, and 2.9 at the leads. and 2/3 was 9.69k ohms at HT and 3 ohms at the leads). I ordered a used set to replace them. The used set came with 1 good coil and 1 bad coil. Swapping the good coil in resulted in it starting but not firing on all cylinders. I ordered two new OEM coils with orange towers and have installed them.
I measured the fuel pressure (36 pounds as expected)
I checked the resistance on the injectors they varied from 15.8-16.6 ohms
I checked that all the injector leads were pulsing with a 12V LED
I manged to find a set of 4 new injectors for cheaper than the cost of having mine cleaned. Installed them and though it still doesn't idle correctly there is no longer fuel pouring out of the union in the exhaust
I replaced the air filter
I replaced the fuel filter
I replaced all the fuel lines outside of the gas tank as they were old and cracking
I installed quick disconnects on my fuel lines that has made removing / installing my tank a lot more pleasurable
I replaced the alternator drive bushings
I replaced the coolant level hose
I replaced the Z engine breather hose (it was cracked and had foamy goop in it)
I checked for vacuum leaks with a propane cylinder
My battery is reading 13.23 volts
When I last started her up she wouldn't idle without me staying on the throttle and when I let off would pop and die. This seems to be the case whether the Throttle Position Switch is connected or not.
The plugs all look good and not flooded
I can rev the engine up to 8,000 RPM in neutral on the center stand with a bit of hesitation around 2,000 RPM and it seems ok
I placed a penny between the throttle body adjuster screw and stop and it seems to idle now.
When I take it for a test ride it feels like it has no power and isn't running like it was previous to the day when it decided to no longer start.
Could anyone suggest where I should go next before working my way through all the other items in the EFI/Electronic ignition K100 2v troubleshooting guide? I'm really hoping to make it the BMWMOA rally in Salem, but at this rate I don't know that I will. I only have two more paychecks before I need to leave. Thank you!
~Ryan