How do i back trace from spark plugs to be sure I will replace the faulty item without spending a fortune on parts? I believe it's one of four possibilities, coil, ignition module, map sensor on the intake or the crank position sensor. I have the service manual but they took all the troubleshooting out and made a manual just for that. I have a 2002 fxd superglide, carborated with 73,000 miles on it.

 

Did it just up and quit on you? Coils (generally speaking) will outlive you. If the map sensor failed I don't know that it would give you a "no spark" condition. Could be wrong on that one. Obviously, a failed ignition module could do it. A failed crank position sensor could do it. When I travel, I carry an extra cps. Apparently it is a known fail point. Now, having said that, I ride an 07 injected bike, and i believe a dead cps will lead to a no spark condition. As for your 02, I don't know for sure. Obviously, having the troubleshooting manual will be your best bet for testing algorithms and that would help you narrow things down a bit. If I were to venture a guess....cps. But don't quote me on that. Not that anything I said helped. Good luck sorting it out.

 

thanks for the input, a couple of other people have said the same thing. So I will replace the cps and let you know how I make out

 

I have a simular problem with my bike, its a FXDL. an 03 model carb'ed. and while riding it at 70 mph down the hwy, it just died! Now no spark out of the spark plug leads and the coil is good from swaping it from another bike checking it. I was thinking ignition module problems but I left stumped on this one. everthing lights up and just no spark. Plugs are new, spark plug wires are new, all fuses are good. What else is there to look at?

 

Jbees: not "saying" the CPS is the culprit but...I don't know how they can be tested...maybe checking continuity across the contacts of a known good one and yours for a comparo shot. Be careful you don't let the "smoke" out. I have successfully let the smoke out of more than one electrical doo-dad...with the usual end result and that is my wallet losing a little weight. But whenever I travel, I still carry a new CPS for my model/year. I think that if you do a little "searching" on this forum and others, you can probably find somebody who has been down the same road as you are traveling. Terribly unlikely that you are the first one to have this problem. Post up when you solve the problem.