Hello, I've been trying to chase down a pesky engine misfire for a few months. Cylinder 4 will randomly misfire on start-up but then seems to run fine for the duration of my commute. It triggers the check engine light but the light will turn back off on its own after a few starts. I had the plugs replaced with OEM since they were due anyway. Replaced every 100k. I'm currently at 300k. I also had the coil replaced on cylinder 4. PCV valve was recently changed as well. Most recently I had the fuel injectors cleaned. None of these services had any change on the condition. And my mileage is still great (42.4 last tank) although I am burning some oil (1000mile/qt). My mechanic measured the resistance on all the injectors and everyone of them was out of spec with cylinder 4 being the worst. So he is leaning towards replacing the injectors. His explanation was that cylinder 4 injector may be opening slowly the 1st time but once it opens it starts functioning normally. Anything else I could try before dropping $700 on the hopes that this is the problem ? Thanks, Keith
Ask your mechanic to do a fuel injector leak down test to confirm equal flow through all injectors. I will look around and see if I can find a good video of the procedure.
Personally I would start thinking about a new engine. Your already eating a lot of oil and that will only get worse. For $1000 you may be able to get a used lower mile motor and have it installed. No way I would invest $700 In a 300k motor. That’s foolish.
I agree ed, maybe change one fuel injector. 2005 TOYOTA PRIUS 1.5L L4 ELECTRIC/GAS Fuel Injector | RockAuto Or just live with it.
I would try another mechanic, only because I don't have $700 to spend on a "may be" for a vehicle with 300k miles. If you trust your mechanic and believe that your fuel injectors are "out of spec", then why not replace them with a set of rebuilts and install them yourself. You can get four (4) fuel injectors that have been cleaned, tested and rebuilt for under $30 including shipping and a ''lifetime warranty" (cough), and if don't need a lifetime warranty for a vehicle with 300k then you can save even more. On a side note, many mechanics (and other professionals) get wholesale or jobber pricing on all part(s) purchases. Example: Four new OEM/Denso injectors cost $640 and installation is $60 (one hour of labor), for a total of $700. Many parts suppliers offer a discount around 20% or more off MSRP, meaning that your mechanic could be making an additional $120 (or more) on just these new parts (which may not fix your problem, please come again).
Where can I get a set of injectors for $30 ? I was going to look into the priuschat injector exchange, I think a set was like $80 if that is still happening ? It's a little too early to junk the motor imo. It still runs good and I think it still has some life left in it and this is really the 1st major repair it's needed but I agree $700 is too much to spend. Keith
swap injector position around see if the misfire moves to that cylinder. You said you had the injectors cleaned. how was that done?
btw have you ever run the engine so low on oil a check engine light came on or the red triangle of death?
4x OEM DENSO fuel injectors for Prius, Echo/Scion xA/xB 1.5L 23250-21020 | eBay and 4x OEM DENSO fuel injectors for Toyota Prius/Echo, Scion xA-xB 1.5L /23250-21020 | eBay There are other refurbished options beyond the two $24.99 listings posted above. If you want to take one for the team you could buy/test a set of four (4) injectors ('New') for $30.99 which includes shipping from California : Upgrade Fuel Injectors set of 4 for 2001-2009 Toyota Prius 23250-21020 New | eBay