I am having a P303 Cyl 3 misfire detected
So far I have:
-Changed the sparkplugs
-Changed the ignition coils
-Changed the sparkplug wires
Still getting a rough idle with the Cyl 3 misfiring.
The head was rebuilt at about 150k miles due to a burnt valve.
The truck sits at 330,000 miles right now.
I'm thinking of getting the compression tested and a valve clearance check. Anyone have ideas before I drop some money into the valve clearance check? If the valve is burnt again, would it be better to find a new engine and drop it in?
I also noticed some engines are 4 port and some are 8 port. I have an 8 port engine, would I be able to swap in a JDM/Refurbished 4 port engine (they seem more available)
You rebuilt the head gasket. It does not hurt if you spend $40 and get the headgasket kit (From Amazon) to test the head again for leak.
Have you checked your MAF sensor and air filter?
Do you have any hesitation when you accelerate hard?
CHeck the headgasket.
Do a compression test. make sure all cyls pass... especially #3
Who's ignition coils did you install? If they came from Advance auto parts they are Sh1t 🙂 Throw them away and get good ones.
Also, check fuel injectors. Toyota's will miss if there is crud in the wire screen in the intake of the fuel injector. Pop them out and turn them upside down and flush them out with the straw of the carb/choke cleaner. Brake cleaner works too. Mine would accumulate minute gritty particles that had escaped the filters for some reason. I had to clean them about every 30k or so. Not sure why. But I would look. When mine missed I already knew where to look.
Do a compression check, both cranking and running. Check for intake manifold vacuum leak, gasket, crack, or bad vacuum line.
