Misfire and Hide Cylinder

[GrisGTI]

I'm looking for some additional help to see if I've missed anything.

My car has cold start rough idle, that appeared after I did a media blast to clean the valves (I had also changed the PCV valve and the water pump/thermostat). It wasn't bad at first, just a sputter every once in a while when cold and showing improvement as the car warmed up. But it progressively became worse until the car registered both an ECP and check engine light. It shows a misfire in cylinder #2. Using OBDEleven I verified that it was only cylinder #2 that is misfiring. I replaced all plugs and all coil packs. Nothing. I switched the coil pack and plug from cylinder #1. Still same outcome—misfire in cylinder #2. I read on this forum that you should do a throttle body adaptation if you have removed the throttle body (which I did to change to water pump/thermostat). I used OBDEleven to run a throttle body adaptation. Symptoms got way worse. Instead of throwing a code sometimes it now throw a code immediately after the idle settled down after start. And it now shows a Hide Cylinder code. I assume it's shutting down cylinder #2. I took the throttle body off to clean it out. It actually looked pretty clean, but I wiped it down some more. I also put a scope down cylinder #2, but didn't see anything obvious.

My next guess is simply a bad injector. Before I spend a good chunk of money on replacing the injectors. Is there a way for me to confirm I just have a bad injector?

What would your next move be? Would you just clean them and put it back together? Or would you spend the big bucks to replace all of them?

 

[Supermoto]

First thing seems to be checking if its the injectors. Swap two around and see if the issue moves to another cylinder.

 

[GrisGTI]

Here's a quick follow up in case this comes up in someone's search. It turned out that the #2 injector has something plugging the inlet. I'm thinking this was my own fault. It looked like walnut media from the blasting I did on the valves. That stuff gets everywhere and I'm wondering if one little piece got in the fuel rail without me noticing. I unblocked the injector, but pulled them as well so i could clean them. I bought seals at the dealership and did a somewhat under-the-table deal with a tech to have him put the seals on for me. I put it all back together and the misfire is gone and she idles great.

One word of caution: Be sure to either vacuum up the dirt on top of the intake manifold or use compressed air to blow it off. If you don't it will spill into the intake ports when you tilt up the manifold to remove it—which really, really sucks.