Missing at higher rpm

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by binthe920, May 16, 2025 at 10:53 AM.

  1. binthe920

    binthe920 Junior Member

    Joined:
    Sep 20, 2021
    2
    0
    0
    Location:
    WI USA
    Vehicle:
    2005 Prius
    Model:
    ----USA----
    I'll try and keep it short, basically my battery in my gen 2 went bad almost 4 years ago, I bought a gen 3 and less than a year later had a gen 3 battery for my gen 2...

    After I put the battery in the other day(finally got to it) it started but was missing, put fresh plugs in it, added fuel system cleaner and filled the tank with fresh gas (had 1 bar of old fuel in it still) now it runs and drives. I can floor it with the brakes on and quick charge the battery but if I try and accelerate too much or try going over 55-60mph it starts missing in higher rpm.

    Bad coil? Dirty injector? The maintenance and check engine lights are steady on, my obd dongle is having trouble connecting so I haven't had a chance to check codes, I know that would help, just hoping someone with experience will know if I'm looking in the right direction. Don't have the tools and space to work like I used to...
     
    #1 binthe920, May 16, 2025 at 10:53 AM
  2. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
    2,637
    1,412
    0
    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    More than likely clogged fuel filter, which is part of the fuel pump. I would try a high concentration of fuel injection cleaner and give it another tank of gas to work it's magic. That stuff will bust loose a lot of varnish and contaminates, so you may end up replacing the fuel pump anyways; but at least you'll have a cleaner fuel system when your do it.:love::cool::p
    This could also be ignition coils, the electrons gotten lazy and the field can't build up fast enough to discharge and fire the spark plugs.

    Happy hunting........
     
    #2 BiomedO1, May 16, 2025 at 11:46 AM
    saneesh8 likes this.
  3. saneesh8

    saneesh8 Junior Member

    Joined:
    Jul 5, 2024
    125
    24
    0
    Location:
    Allen, TX
    Vehicle:
    2009 Prius
    Model:
    One
    Exact same symptoms on my bmw z3. It was the fuel filter. Luckily on that car, it is separate and mounted under the car.
     
    #3 saneesh8, May 16, 2025 at 1:43 PM
(You must log in or sign up to post here.)