Hi,
I have a 2003 EFI Fatboy. I need help with sorting out an ignition problem. The bike has been laid up for two years. It has been stored inside and the bike was running fine before I laid it up. I have fresh petrol, a new fully charged battery.
With the plugs out, I may get a spark at one or the other plug after turning the engine over the starter motor on the 5th or 6th attempt and then it would only be one spark as the engine stops on the starter. If I try and crank it over on the 15th or so attempt I can get a nice consistent spark from both plugs. But then when I crank it over again, we are back to the same intermittent scenario. I have fitted new plugs, cleaned the grounding connection from the negative side of the battery, cleaned the connectors on both relays. I have removed one HT lead from the coil and replaced with a solid piece of copper wire with a small gap away from the cylinder. I get the same result as mentioned earlier. My local HD Dealer has suggested the crank shaft sensor and a cost of supply and fix at around €300 plus lifting the bike.
I don't wish to take it to a dealer if I can at all avoid it. Has anyone any ideas of where I should be looking next and are ther any tests which can be performed on the coil, wiring, and crank sensor.
Any help would be much appreciated. Thanks.

 

I would be suspect of anyone making suggestions to replace parts before doing any hands on diagnosis. A substitution mechanic could eventually solve the problem, but at a higher cost to your wallet.

Have you tried pulling any trouble codes stored in the ECM. Start there. If no trouble codes then you could have a number of issues. Based on it sitting as long as it did, if it sat with fuel in the tank. The filter may be clogged, causing incorrect fuel pump pressure which would cause the intermittent spark (no fuel pump pressure signal to the ECM, causes no spark signal sent out to the plugs from the ECM). Check for battery voltage at the fuel pump relay.

Your best bet would be to obtain a copy of the service manual, and follow the troubleshooting flow charts.

 

Larsum,
Thanks for your reply. It got me going in the right direction. I got hold of a manual and started working through the trouble shooting. There were no current or historic fault codes. I read in the manual that the injection engine wont send a spark to the plugs if the plugs are out of the head! (Injection engines are new to me). Put the plugs back in, crank the motor over and the plugs are sparking fine. Took the plugs out, poured about 15 ml. of gas into each bore, put the plugs back in and fired up the bike. It fires up first push of the button each time now. Now its not something I read in the manual, but its something I've often done with carb motors to see if they will fire. Not sure what the problem was, other than the bike had been standing a good while and and was a fuel problem rather than the sparks. Just a reminder to anyone reading this thread, you can not check for a spark at the plug unless their is a plug in the head. I think the ECM is able to sense if their is compression or not.
Rockabill

 

So it is running all right now? That's good to hear. Thanks for posting your results. You may help another forum member at some time with this info. Ride safe.