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Old 01-12-2015, 12:38 PM   #1
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Default Cylinder 4 misfire

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?
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Old 01-13-2015, 08:42 AM   #2
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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?
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Old 01-13-2015, 12:11 PM   #3
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Originally Posted by guttedmiata View Post
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..
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Old 01-13-2015, 02:54 PM   #4
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Assuming your injector isn't clogged isn't the best idea. Try to swap injectors around and see if the misfire changes?
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