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Front cylinder not firing

bkrdr40

bkrdr40

Member
I have an 08 Nightster with only about 2200 miles on it. I put 1000 miles on it then had the HD service done. After that I installed V&H shortshots, SE high flow filter kit, and a TFI fueler. Just last week I rolled the bike down the driveway to head off to work only to start it up and realize only one cylinder was firing. After some initial troubleshooting I found the following; spark is fine, does not seem to be getting any fuel into the cylinder. Checked all the connections between the TFI and the injectors and they seem fine also. LED lights are blinking which according to Dobeck is an indication of a bad wire. Seems plausible to me but I tried one other thing just to see if the injector was working, I hooked up the factory injector cannon plugs and it still is only firing on the rear cylinder. Also the battery is not holding charge well, have to charge it prior to troubleshooting or it won't start. Could the injector be bad so soon? Is the TFI defective?

Any suggestions are welcome.
 
If you bypassed the TFI and it still doesn't fire, then the problem could be an injector or the wiring to that injector, it could also be an intake leak to that cylinder causing it to be lean and not fire properly. The charging problem is something aside from the injector problem. Even a new part can be bad.
 
Thanks Glider, is there any way to troubleshoot the injector while it's on the bike like with a multi meter? Does the factory injector plug feed power to the TFI plug?
 
Without a meter, it's difficult to tell anything. The injector wire fired off the injector with low voltage, you can try to wiggle the injector wire at the injector to see if the injector works while you move the wire but the best way is to get an inexpensive digital multi meter and check what voltage you have at that plug.
 
Thanks again Glider. I have a meter, can you tell me what voltage range I should be looking for off the plug, and also should I test the TFI plug or the factory plug or both?
 
Test the plug that was the factory plug that you removed to install the TFI plug. I believe you should see 5 volts.
 
Glider, I checked the voltage at the bike plug and got about 30 volts, then I plugged in the TFI and checked the voltage there and got around 5. Could it be possible that the injector is bad after 2167 miles? Not sure what to do next but take it to the dealership.
 
That is what I got from the bike injector plug with the TFI unhooked. Also verified that the lights on the TFI are operating normally, so no indication of bad wiring there. I'm really at a loss as to what's going on here with essentially a brand new bike. I hate the thought of going to the dealer for help because I know I'm just a dollar sign to them.
 
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