Misfire on idle
01-27-24, 10:52 AM
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Misfire on idle
I’ve been getting codes for multiple misfire and misfire on cylinder 1,3,4,5 only on idle the misfire count goes up I changed spark plugs and coil packs and still misfiring any ideas or someone’s whose experienced this before ?
02-13-24, 08:52 PM
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i’m dealing with the same thing, runs fine but at idle it’s misfiring all of bank1 (cylinders 1,3,5,7) i’ve changed spark plugs which helped a little and swapped coil packs aswell as verified i don’t have any vaccum leaks, im guessing my timing might be a tooth off so i have the aisin timing belt kit ready, or the injectors might be gunked up
02-15-24, 01:21 PM
#4
Instructor
For troubleshooting, first step always is to provide the engine diagnostic trouble codes (DTCs). If you have misfiring without the P0300 code, that means misfires were detected and recorded at different times. Existence of other codes can help pinpoint the problem before you start changing out random parts. Check freeze frame records to see what was going on at the time of misfires - engine warmed up or not, air-fuel ratio lean or rich (see STFT and LTFT for bank 1 vs bank 2), etc.
Running the engine while misfiring is going to overheat and melt your three very expensive catalysts, so my recommendation is to only turn the engine on for troubleshooting purposes.
Misfiring at idle indicates something with the variable valve timing system. Have you checked your oil control valves? Check forums here for OCV cleaning/replacement.
That being said, I solved random all-cylinder misfiring on a Honda V6 by installing remanufactured injectors from RockAuto. I used a $15 spark tester to visually ensure spark was firing on each ignition coil harness even while wiggling the wires, which ruled out issues with the harness and electrical system. I installed new coils and plugs, new engine coolant temp sensors, yet random misfires continued. The next easiest step was replacing injectors, since it wasn't my car and I wasn't going to spend money on a fuel pressure gauge set. This reduced the misfiring to one cylinder, and after moving that new injector around and the problem following, RockAuto did a fast and free exchange for another remanufactured injector, and the problem was fully solved after.
To clean injectors: bypass your fuel line, screw a can of V8 (bigger can than the V4-V6 cleaner) Toyota Pressurized Fuel Injector Cleaner into the fuel line, and run the car off that can until empty. This cleans your injectors with concentrated detergents that are not safe to feed through the fuel tank. The pour-in-tank cleaners don't work as well, but you can try Royal Purple Max-Clean or Toyota EFI Tank Cleaner and mix with the least amount of fuel per bottle's directions.
To verify injectors: remove them, apply battery voltage, and ensure they fill a graduated cylinder to 60-73mL every 15 seconds, and that the difference between each injector is less than 13mL. The injector should also leak less than 1 drop every 12 minutes.
With your injectors removed, you could take them to a shop that can do an ultrasonic cleaning.
If you can't be bothered with all that, you can buy remanufactured injectors and return old ones for core refund. Reman injectors do the detergent and/or ultrasonic cleaning process and then ensure spray volume vs time meets factory spec.
Always buy top tier certified fuel to keep injectors clean - see https://stationfinder.toptiergas.com/
Running the engine while misfiring is going to overheat and melt your three very expensive catalysts, so my recommendation is to only turn the engine on for troubleshooting purposes.
Misfiring at idle indicates something with the variable valve timing system. Have you checked your oil control valves? Check forums here for OCV cleaning/replacement.
That being said, I solved random all-cylinder misfiring on a Honda V6 by installing remanufactured injectors from RockAuto. I used a $15 spark tester to visually ensure spark was firing on each ignition coil harness even while wiggling the wires, which ruled out issues with the harness and electrical system. I installed new coils and plugs, new engine coolant temp sensors, yet random misfires continued. The next easiest step was replacing injectors, since it wasn't my car and I wasn't going to spend money on a fuel pressure gauge set. This reduced the misfiring to one cylinder, and after moving that new injector around and the problem following, RockAuto did a fast and free exchange for another remanufactured injector, and the problem was fully solved after.
To clean injectors: bypass your fuel line, screw a can of V8 (bigger can than the V4-V6 cleaner) Toyota Pressurized Fuel Injector Cleaner into the fuel line, and run the car off that can until empty. This cleans your injectors with concentrated detergents that are not safe to feed through the fuel tank. The pour-in-tank cleaners don't work as well, but you can try Royal Purple Max-Clean or Toyota EFI Tank Cleaner and mix with the least amount of fuel per bottle's directions.
To verify injectors: remove them, apply battery voltage, and ensure they fill a graduated cylinder to 60-73mL every 15 seconds, and that the difference between each injector is less than 13mL. The injector should also leak less than 1 drop every 12 minutes.
With your injectors removed, you could take them to a shop that can do an ultrasonic cleaning.
If you can't be bothered with all that, you can buy remanufactured injectors and return old ones for core refund. Reman injectors do the detergent and/or ultrasonic cleaning process and then ensure spray volume vs time meets factory spec.
Always buy top tier certified fuel to keep injectors clean - see https://stationfinder.toptiergas.com/
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