EFI Flat spot at 3000 RPM

Discussion in 'Engine, Fuel and Exhaust' started by jmoran3, Apr 6, 2014.

  1. jmoran3

    jmoran3 Member

    I have an issue with my 2005 FLHTi. I have scanned a lot of the posts here and it gives me a lot of good info but,, I don't see what mine is doing so here goes,,,, and thank you

    The bike starts and seems to run fine. After a long Winter in NY,,, I was hoping I just had to run some fresh fuel through but,,, after two tanks and some fuel injector cleaner,,, the problem is still there.

    Problem; The bike seems to have a huge flat spot between 2800 and 3200 RPM. After 3000 RPM, the engine seems to be breaking up and acts like it's out of fuel. As soon as I release the throttle, the bike goes back to normal and seems to be OK. It has gone past the 3000 RPM mark several times and has all the power and range it should but the flat spot and misfiring seems to be increasing.

    A lot of the posts seem to point toward the fuel filter or pump inside the tank but there are several that suggest hoses inside the tank.

    Does anyone know what the flat rate might be to get into the tank and check it out? I don't really have the special tools that seem to be required.
  2. dolt

    dolt Senior Member Contributor

    Before you go down that road, does the flat spot exhibit with a full tank of gas? If so, a leaking fuel supply hose is not the issue. Although, there is a high incidence of this problem occuring in the '05 model year, particularly in the softails. The location that the hose will rub and make a hole is far enough down in the tank that the bike will run fine on a full tank and start to exhibit the problem after the fuel level drops below the line puncture and air can leak in.

    The dealer or indy can check fuel pressure to verify whether or not the pump is functioning properly. In either case, there are no special tools required to make either repair. Get a service manual and DIY the repair.

    Another thing to check is fuel injectors and fuel injector wires; another fuel delivery component. The connections can become loose and at certain RPMs they lose connetivity and interrupt fuel delivery. Injectors can and do go bad as well.

    I don't know about your dealer but most these days don't employ real techs; they employ parts changers. They will change a part, give you the bike back fixed or not, usually not and you will be back the next week so they can change another part; rinse and repeat. If you are not capable or don't want to go the DIY route, do some investigating locally to see if you can find an independent tech with a good reputation. On the other hand, if you have a high level of confidence with your dealer's service manager and their techs, let them have a go at fixing the problem.:coffee

    Let us know how it goes.
  3. Amish Hawg

    Amish Hawg Active Member Contributor

    +1 with Dolt's advice. A manual, basic tools and a couple hours. You can save some Major money for chrome. DIY

    I had similar issues, look at your throttle body shaft for a crack.