Misfiring Problem with my 2002 Vulcan Classic 1500 FI.

[lylemills]

I am all of the sudden having trouble with my 1500 Classic FI (2002) misfiring after warming up. Due to the increased electric demand of the FI. I am wondering if a week battery could be the culprit. It's a 2002 1500 Classic FI and still has the origional factory battery in it. (4 years old) and the bike still starts fine. If I am dreaming don't hesitate to tell me. And if anyone has an idea as to what the problem could be could you guide me in the right direction? Would hate to take it to the dealer, for something simple. $$$

[NY_Guy]

Unless there's a problem with the ECU, I don't think its current is the issue (driving lights or air horn consumes more amps/volts). Have you pulled the plugs to see if there's carbon build-up? You might also try some Sea Foam-- people on this forum have had good results with it. If electrical, more likely the rectifier or possibly a coil.

[lylemills]

Originally Posted by NY_Guy

Unless there's a problem with the ECU, I don't think its current is the issue (driving lights or air horn consumes more amps/volts). Have you pulled the plugs to see if there's carbon build-up? You might also try some Sea Foam-- people on this forum have had good results with it. If electrical, more likely the rectifier or possibly a coil.

Plugs clean. just ran a can of seafoam through it about a week or so ago. I cleaned the plugs and took for a ride, got about a mile or so and it started acting up again. Would pulling the codes from the ECU be of use? I tend to lean toward electrical, I'm thinking a bad coil. Cause it only starts acting up when it starts to get warm. And the coils would probably get warmer faster than the rectifier. Could be a plug wire starting to break down, the salt air down here in Florida does some strange things to motercycles.

[lonestar]

I think you are right that the problem is electrical in nature. Check all your connections to the battery and if you did not solder your connections on your ECU it would be a good idea to do so now. I had a short under the seat in my wiring harness that caused all kinds of problems for me until it was finally diagnosed and the whole harness was replaced. It was strange because it did'nt do it all the time. Have you blown any fuse's? Mine kept blowing the ignition fuse. Pull the seat and look very carefully at thunderside of the harness for any spot where it may be worn through and touching the frame.
Good Luck!
Lonestar

[lylemills]

Originally Posted by lylemills

I am all of the sudden having trouble with my 1500 Classic FI (2002) misfiring after warming up. Due to the increased electric demand of the FI. I am wondering if a week battery could be the culprit. It's a 2002 1500 Classic FI and still has the origional factory battery in it. (4 years old) and the bike still starts fine. If I am dreaming don't hesitate to tell me. And if anyone has an idea as to what the problem could be could you guide me in the right direction? Would hate to take it to the dealer, for something simple. $$$

Thought this would be of intrest to some of you all. The problem all boiled down to a bad (defective?!) spark plug. Plugs were only about 1000 to 1500miles old. On the cylinder that was missing it was the rear right side plug. The only one that I found a brown ring arround the insulator not on the business end but on the glass insulator right above where the ceramic and the steel mate. See attached document. Spoke to a mechanic friend of mine that works on high end import autos. When I told him on the phone what I found he did not even hesitate, he said that this plug was shot, I just described it to him he didn't even look at it.

Just installled a new set of plugs, and rode the bike for about 10 miles and no miss!!!! With the bad plug the bike would start missing within about 1-2 miles of riding. Looks like the mating process (ceramic to steel) failed on this particular plug. I have never in 30 years of riding seen a plug do this. And I have owned 2 harleys (older models) and have seen some ugly spark plugs come out of them often. But nothing like this, The brown ring looked like baked on oil and could be scraped off with a finger nail. Would be intrested in knowing if any one else has seen or heard of this? This problem has been pestering me for about 3 weeks now. Thought it was a wire shorting or possibly a spark plug wire breaking down. Isn't it amaizing how it's the simplest things that we over look when there is a problem.

Lyle

2002 1500 Classic FI.

Mods

VH Longshots. (open)

[Cabo]

My bike started missing and I changed the plugs but it made no differance. I took it in since it is still under warrentee

[Gryff63]

I too have this issue but with an 03 nomad. Not the misfire but a definite stalling. ECU shows no faults, plugs changed, air filter changed, seafoam ran through it. premium gas only. problem arises sporatically. This morning, no issues, yesterday, like riding a bronc, hard to keep running.

[Madsdad]

My bike just started this the other day. when it gets up to operating temp. it dosent want to idle. If you stop in traffic, you have to keep it revved to keep it running. it will also misfire occasionally going down the highway. Either time, the FI light comes on.
I have changed plugs, tried Seafoam, tried Heet, removed the ECU and checked the wiring, checked the wires at the battery, checked the ground wire on the engine, checked every wire I can see for chaffing etc...
I noticed today, it was running fine, and after about a 20 mile ride I stopped to get a drink. When I started to leave I had to really rev the engine and slip the clutch to get it on the highway. Once up to speed it ran fine. About 50 miles later I stopped for lunch, same problem. I went on with my trip for about another hundred miles, got mad at the bike and started heading back home.
Ya know those cartoons with the cloud over the guys head raining on him? That was me, literally ! ! I rode all the way back home in the rain with a misfiring bike. (you can eliminate the rain as a factor because it was running bad before he rain started ) LOL
Any ideas?

[Gryff63]

[quote=Madsdad;724820]My bike just started this the other day. when it gets up to operating temp. it dosent want to idle. If you stop in traffic, you have to keep it revved to keep it running. it will also misfire occasionally going down the highway. Either time, the FI light comes on.
I have changed plugs, tried Seafoam, tried Heet, removed the ECU and checked the wiring, checked the wires at the battery, checked the ground wire on the engine, checked every wire I can see for chaffing etc...QUOTE]

Sounds like a a similar issue I had. I finally put mine into the shop and told them what I was epxeriencing. Took many hours of diagnosing, but they claim to have found a wire that was busted and fixed it. NOw it runs great. I added the Techlusion TFI and a Hyperthruster air ram to my machine and will put on vance and hines exhaust this winter. Get less mileage now but boy do I have power. Get your shop to run a full diagnostic on your bike. I too couldnt find any loose wires etc.