Recently got p0300 misfire at cold start. Changed sprk plugs already.
It's 120k. Feel might be the injector seal or intake valve clean .
Want to try clean intake carbon 1st .
Any one knows a good shop ?
Recently got p0300 misfire at cold start. Changed sprk plugs already.
It's 120k. Feel might be the injector seal or intake valve clean .
Want to try clean intake carbon 1st .
Any one knows a good shop ?
Why would you want to have your walnuts blasted?
2010 Mazda3 Graphite Mica GS Auto with Comfort Package
Car has 120k , never touch intake valve. Must be so dirty.
No. I don't think that is a certainty. Cars run pretty clean these days. Back in the day before modern fuel injection where carbs would run rich, then yeah sure.
Don't guess. If you determine you need an intake cleaning then take it for a motorvac. But there are other things to consider. Did you check your coil packs when you changed your spark plugs? Maybe one is going bad or you have a corroded connector. Listen around the intake manifold with a stethoscope for a vacuum leak, etc.
You obviously know nothing of the Mazdaspeed platform. They're direct injected and the valves are known to get caked up pretty good because there's no fuel flowing over them like normal port injection.
It may or may not be the cause of the misfire...coil pack is probably more likely...but it certainly is good for the car.
- 2021 Porsche Macan GTS -
- 2016 Lexus NX200t F Sport -
- 2010 Mazdaspeed 3 Black Mica - SOLD -
Sry I forgot mentioning it's 2010 stage2 speed3 20psi, Never clean intake valve. No occ.
Should I clean the coil packs or just replace them ?
There's nothing to clean on the coil packs...misfire could come from a faulty one and would need replacing. That said, it's multiple cylinder misfire with that code which would point to something else being the problem (since only one coil pack usually goes at any given time). Could be a fuel problem, MAF/o2 problem, compression problem (worth doing a compression test), and a few other things.
D'oh! I need to pay more attention
Well you could check that they fit snug on the spark plug. If you had a wire brush you could give them a once over.
I think if you had a left over spark plug you could use that to test each coil individually.
https://www.youtube.com/watch?v=mQp8qYInv2U