So, this weekend's camping trip was to Ipswich with the Suffolk Sidecar Club. I loaded the outfit and set off at about 10 on Friday morning. Some 70 miles later at Higham Ferrers I stopped to fill up with petrol and then disaster, I couldn't get it started again.

After fiddling around for an hour or so, I was obliged to call the RAC and get returned to home on the back of a truck.   

Arriving home at around 5 in the afternoon, it was a panic re-packing of all my gear (of course needing some different kit) onto the solo K, eventually setting off for Suffolk at about 6. A subsequent blast down the M6 and A14 rather than a prettier route meant that I arrived in Ipswich with time to get the tent sorted well before dark, but, sadly, too late for the traditional fish and chips dinner.

Tomorrow I'll go through CF's excellent trouble shooting guide (see the portal page if you haven't yet discovered it) looking for the problem.
The RAC man's injector pulse checker showed no signal to the injectors, so that's my starting point.

Happy days ahead for me.

Paul.

Would suspect the FI relay, did you hear the fuel pump when releasing the starter button?

Yes, Inge, the fuel pump was running and I could feel pressure in the fuel lines. I was suspecting the temperature sensor but tonight I measured 2.3K ohms at pin 10 on the EFI connector.

Paul.

As the fuel pump did start the injectors also is receiving power....as long the
connector between frame/engine harness is OK.

Then it would be the signal to the injectors which relies on the hall sensor
signal.......checked for spark, or signal to the coils (both)?

Thanks Inge, I'll check those points first and report back tomorrow.

Paul.

Well, started today by checking sparks; yes all there and the engine did fire once but wouldn't run.

So, off with the tank, dead easy with 'quick fuel connectors', and check all the values at the FI connector and the ignition black box. I didn't find anything untoward, so all I could do was 'DeoxiT' everything in sight (again).

I did find one connector that I'd never had apart before, the in-line connector between the injector loom and the main loom. It didn't look particularly corroded but it got the requisite forum treatment of course. All the earths were pulled apart and cleaned.

On refitting the tank the engine started and ran OK. I ran it until the fan came on and then checked the resistance at pin 10 on the FI connector; about 300 ohms, so that confirmed that the temperature sender was working properly. 2.3K cold, 300ish hot.

I was a bit disappointed that I didn't find anything definitely at fault, but as I previously had no pulse at the injectors, it could have been a high resistance at that connector to the injectors.

I'll now carry a copy of CF's troubleshooting guide, a multi-meter and the injector pulse checker (made today as CF's instruction) in the sidecar in case the problem recurs. I never want to have my bike brought home on a truck again.

Keeping my fingers crossed,
Paul.

sidecar paul wrote:Well, started today by checking sparks; yes all there and the engine did fire once but wouldn't run.

So, off with the tank, dead easy with 'quick fuel connectors', and check all the values at the FI connector and the ignition black box. I didn't find anything untoward, so all I could do was 'DeoxiT' everything in sight (again).

I did find one connector that I'd never had apart before, the in-line connector between the injector loom and the main loom. It didn't look particularly corroded but it got the requisite forum treatment of course. All the earths were pulled apart and cleaned.

On refitting the tank the engine started and ran OK. I ran it until the fan came on and then checked the resistance at pin 10 on the FI connector; about 300 ohms, so that confirmed that the temperature sender was working properly. 2.3K cold, 300ish hot.

I was a bit disappointed that I didn't find anything definitely at fault, but as I previously had no pulse at the injectors, it could have been a high resistance at that connector to the injectors.

I'll now carry a copy of CF's troubleshooting guide, a multi-meter and the injector pulse checker (made today as CF's instruction) in the sidecar in case the problem recurs. I never want to have my bike brought home on a truck again.

Keeping my fingers crossed,
Paul.

Nice to see you back on the road. I know the feeling about fixing the bike without knowing what was the problem. This is irritating and you always wonder if the problem will recurs.
I already carry a bit of documentation on paper, but one thing that I was thinking of, was to copy all my documentation on a CD and carry it with me all the time.
If you break down, you will always find somebody with a computer to consult your CD.

By the way, I am still receiving thank you Emails from all over the world for what I wrote on the EFI troubleshooting. I also have requests to do the same thing for other BMW bikes but it was an exhaustive investigation just for the K100 and I don't have the energy to do it for others.

Cheers and happy motoring.

CF

oops missed that one paul
good to see you got it running again ...yippee

Paul

Sorry to see that trouble but glad you got away. I have also travelled that A14 M11 route many times and it most certainly does not compare with the back roads which I have also enjoyed.

But ones mans troubles can bring another gem. Quick fuel connector? 88KE and myself were discussing the idea of quick release connectors while looking at the connectors from a petrol tank to an outboard engine and thinking how good it would be to have something like this on the K. I was about to embark on a search for something suitable but you seem to be there already.

But having had a problem on the L T where I had a cut out, fuel pump running and no starter turning it I swapped the ICU but feel it was a less than perfect connector pin at the ICU was the true cause of the problem. I would have to test the old unit to be certain but as the problem had remained after swapping relays and cleaning earths, connections etc I know it wasn't a fault elsewhere. Problem never repeated.

Hi 92KK, here's the link to how I did my fuel line connectors.

https://www.k100-forum.com/t3308-fuel-line-connectors?highlight=fuel+connector

Paul.