Hi
Having a problem with my 03 Ultra Classic. I'm hoping someone has seen it before. The bike runs great in the morning but as the day heats up ( 90s )
the motor starts missing from time to time. It is getting worse so soon It will show itself but man I hate trying to push a Electra Glide home.

 

Clear plug leads are secure and maybe put a new set of spark plugs in to see if that fixes it.

 

Original plug wires? Might be time to change those as well.
Have you thought to check for codes?

 

Check intake for leaks,start engine spray some wd around flanges listen for engine to rev up.

 

All the above are good suggestions.

Another thing to check is when the coil is on the way out when it heats up it can intermittently go open on cyl only causing misfire.

But bad plug wire ,resistor going bad in a sparkplug or plug itslef bad,poor elec connection on injector or when inj gets hot maybe its hanging up requiring a good cleaning (Chevron's Techron concentrated injector cleaner @ 1.5oz per gal fuel is good for that),intake leak or injector seal leak are often the cause of an intermittent misfire.

Happy motoring.

Scott

 

I had a bad plug wire cause this problem on my RK. It got worse and worse. I had actually replaced the stock wires and had a ton of miles on them. Put the like new original wires on and no problems.

Head

 

Thanks guys. Have new plugs and wires are on the way. Old wires have about 25000 on them so could be the prob. If not I have directions to go in now. Guess I'll throw money at it until I hit the prob. I need my road truck back. Thank again.

 

If that doesn't fix it check the front injector wiring. I had an intermittent miss and I found that the wire was broken inside the insulation. It looked fine but if I pushed and pulled in and out on the wiring I could get it to miss.

I posted the part number for the injector pigtail somewhere on here if you need it. Just do a search.

Good luck.

 

Try swapping out your engine temperature sensor, they're like $35 so it's a cheap place to start.