Hi everyone, So I just bought a 2010 mustang gt and it keeps having a misfire in cylinder 2. So this only happens when my car sits for a period of time and usually on cold days. It idles at 1500RPM on those days when I start it after having the car sit for a day or so, also the first 30 seconds the car is running it misfires 130 times and you don’t feel any of it just the high idle . So I myself changed all the spark plugs and the coil pack for #2 and then cleared the code hoping that was the last of my issues. Then again it came back on and I once again cleared the code. Then again it came back on so I put injector cleaner in the car and it came right back on a week later. So I gave up and gave it to my cousin who owns a shop, he looked into it and he said he has no real like answer just what he thinks could cause it. He took off the intake manifold to check/replace the intake gasket and when he took it off he saw that it was fairly new and same with the cylinder 2 injector so he saw that someone had been chasing the same problem I am currently. So he replaced the gasket just to rule it out and swapped the cylinder 2 and 1 injectors to see if/when the code pops back up to see if it’s changed. He also talked to one of his Buddies that’s a ford technician and they recommended foam. But if the issue isn’t solved by any of what he did or seafoam his best next educated guess would be the lifters. Anyone have an opinion on this?

 

If it's for sure the single cylinder, number 2... then these are the suspects (I'm going to list them all, regardless of whether y'all have checked them or not.)

Compression is down, that's a ring/piston issue or a valve issue.

No fuel. Injector. Injector electrical connection.

No spark. Spark plug. Coil pack. Coil electrical connection. Wiring issue between coil and computer. Computer issue.

Cylinder can't get air. Intake runner blocked or valves not opening. (not very likely.)

Cylinder can't expel exhaust. Blockage of passage or valve will not open (that is actually possible.)

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Given all you've done (spark, coil, injector, foam, intake gasket) it appears there's a lifter not working. I'd guess exhaust cam follower/lash adjuster is the possible here. Btw, they're not lifters, as some would vociferously exclaim, as me how I know. At idle one of the two intakes valves opening on that motor should allow enough fuel/air to idle if the other isn't opening. It wouldn't hurt to lift the valve cover and have a peek. Might find that somehow the cam follower has fallen out because the lash adjuster is worn out. Which would be a real interesting thing, as that would probably drop a valve, grenade that piston, and definitely make a new head/camshaft be a thing. One hopes not.

But still... it does happen:

Let's think positive thoughts. Hopefully it's a bad connector at this point.