Hey guys. I just recently had my engine out to fix a stuck oil pressure relief valve and now that I got everything back in my engine has a miss in the 4th cylinder. I'm getting spark and fuel and the compression for all the cylinders are similar. The only thing I can think of is maybe my timing is a tooth off. I'm going to try and get a picture of my cams here soon but they seem lined up right. Would the timing being a tooth off only cause a miss in the last cylinder?

 

No, cam timing being off isn't going to cause a single cylinder to change. What did you do to verify spark? How did you determine it's #4?

 

I took the cop out and put a spark plug in it to check for spark. I figured maybe my cop was bad so I swapped front to back but still had the miss. Also changed out spark plugs with no luck. As to how I know it's the back, I took turns unplugging my cops and the car ran the same with #4 plugged in as plugged out. For some reason, it's not firing and the car was running perfect prior to pulling the engine so I doubt that my #4 injector could have become clogged during that time. Compression was still good in the cylinder and I only ran it a second without oil pressure so it shouldn't be my rings. I'm running out of things to check..

 

Assuming your injector isn't clogged isn't the best idea. Try to swap injectors around and see if the misfire changes?