Misfire after head replace

[ike84]

I agree with blue. The "correcting" of the vacuum deviation would suggest that the problem is not static, and lifter sticking can do this. I would sea foam the intake and crank case to see if that makes a difference. From personal experience I can tell you that this can fix sticky lifters so long as nothing mechanical is broken.

[Gilles]

Originally Posted by ike84

I agree with blue. The "correcting" of the vacuum deviation would suggest that the problem is not static, and lifter sticking can do this. I would sea foam the intake and crank case to see if that makes a difference. From personal experience I can tell you that this can fix sticky lifters so long as nothing mechanical is broken.

You may want to try something like this, a friend of mine that runs a P specialty shop suggest it for my 987 and the tapping noise went away:

https://www.turnermotorsport.com/p-582224-hydraulic-lifter-additive-300ml/?gclid=CjwKCAjwybyJBhBwEiwAvz4G7_7EyNy5NBzAx_Khm3f kZokxq9bUiG5eFhCIXQFegScyqdBKQSnrpxoCRNAQAvD_BwE