07 Dyna starts hard when hot

Discussion in 'Engine, Fuel and Exhaust' started by byuddy, Apr 16, 2009.

  1. byuddy

    byuddy Member

    My '07 FXDL (bought in Oct '06) usually, but not always, starts hard when it's hot. It cranks and bucks and sounds terrible. Sometimes it backfires. When I let off the starter button, I can hear what sounds like the fuel pump running over. The problem has persisted since day 1. It takes a couple of attempts, but it always starts.

    And it always starts fine when cold. Sometimes it starts fine when it's hot. Often the noisy restart happens after I have stopped to refill the gas tank. I have reported the problem to the dealer, but they have not so far been able to fix the problem.

    Last October, just before my warranty was up, I had the dealer try one more time. They replaced the starter clutch on warranty. I also had them do the 10K service. Of course I was not able to take a test ride until yesterday (Minnesota weather). Unfortunately I still have the problem. I plan to call the dealer one more time. I expect they should be able to fix the problem under warranty because the problem is well documented.

    I wonder if there is a special ECM sequence that controls fuel when starting. Maybe the ECM is sensitive to heat and it has trouble only when it's restarting a warm engine. I have not heard of heat problems with 07 Dynas. Just guessing.
  2. glider

    glider Veteran Member

    There are dealers that can fix things and others that can't find something unless it sticks them in the eye.

    It could be a few things like the cylinder head temp sensor located on the rear of the front head or even fuel mixture once the engine is warmed up. You didn't mention anything about a tuner on the bike but most times the factory settings are very lean and hard warm starts can prevail as a result. I suggest if you have no tuner to get something like the TFI to add some fuel. It will run better and it then gives you adjustability with the FI system.
  3. Spade5

    Spade5 Active Member

    I think I experienced the same thing on my 07 Wide Glide. Mostly it is after gassing up. Sometimes it is sort of a lurch and other times kind of a cough.

    I also think part of the problem is me - as Glider thinks why does that not surprise me. I tend to believe he is spot on about the lean mixture when warm as opposed to cold.

    I have learned to give it another 10 seconds or so after the check engine light goes out before trying to start. Also, I think I was anticipating that it would start quickly like when cold and was releasing the start button too soon. I have learned to not release it until it actually starts. It may have to roll over a couple of times but this method has not failed me yet.
  4. byuddy

    byuddy Member

    That idea is interesting. My bike is stock, except for drilled out muffler baffles. Up until last summer, the bike was totally stock. I have considered getting slipons, air cleaner and a tuner so as to make better sound, and getting a performance boost. Running cooler would definitely be good.

    Last summer I tried only the slipons (old SE II and Khrome Werks) but they were a little loud for me, and the bike didn't perform as well.

    I'll try giving it another 10 seconds after the check engine light goes out. I learned very early on about not taking my thumb off the starter too soon.

    I'll also check out the TFI.