I can't fix a miss. Any advice very appreciated.

I have an '08 V8 Sportrak limited that developed an intermittent miss with no engine codes. It has about 70K miles on it so I figured it's just time to change the plugs. They had never been changed before so that went about as well as you would expect. Once I got the broken pieces out of the two affected cylinders and scoped them out with my Snap-On borescope, I finished putting in the plugs and changed all the coils just for the heck of is.

My wife drove it to the store and reported that it still ran rough then it threw a code that the #2 cylinder wasn't firing. I replaced the fuel injector and both the coil and injector connectors in case there was a short. Still got a code on #2 .

Next I checked the compression and it matched all the cylinders on that side.

What am I missing? Are there any common things I should know about?

Hi, im not a master mechanic however I am old school and have ran across this problem many times. While reading your post my first thought was a cracked head or blown head gasket, however you checked the compression which rules that out. With all that you have replaced it appears that there is only one thing left unless you overlooked an electrical problem. If everything else is working properly, this leaves a leaking intake manifold gasket or a vacuum leak. I would recommend checking all vacuum lines going to the intake, some can be nearly impossible to find. If one isn't found by eyesight you can use carburetor cleaner spraying all hoses and connections while the engine is running. Be sure to check the EGR (if equipped) to assure that it is working proper. If none of the above are the problem, then it's very possible it's the manifold gasket. The manifold can be checked by injecting air into the cylinder with a fitting that screws into the spark plug hole. Check each cylinder one at a time making sure both valves are closed and listen for air in the (throttle body), (check the exhaust) and (check for air in the crank case) or [oil filler cap]. If air is in the crank case then there would be a problem with the rings but shouldn't be. USE CAUSTION WHEN DOING THE AIR TEST THIS CAN CAUSE THE ENGINE TO ROTATE. One more thing if you get air through the T/B or the exhaust it could be the intake gasket or a burnt valve. Any of these situations will cause a skip or miss that no spark plug or injector will fix. Please let me know if this is any help, and GOOD LUCK gtate!

It's been a while since I started this thread. I thought the resolution may help someone out if they have the same issue.

My radiator cracked between the main container and the oil cooler causing my engine to slowly get inundated with water. By the time we figured out what was going on, I had to replace the engine.

The moral of this story is, the radiator is a PoS that you have to keep an eye on or you will regret it later on.