@jrichker thank You for detailed post. Gone thru half of that...still to do...
Anyways, I done like dozen of Cylinder Balance Test and every time I get 9 9.
Done something this weekend.
I changed sparkplugs from Motorcraft 42 to NGK UR45. Old sparkplugs by the book, perfect... Picture attached.
Inspected all pistons. See attached pictures, seems to me like carbon buildup. I hope so. Getting worse to back of engine. Clogged PCV may contributed this buildup...dunno if PO knew that. I am a little bit worried, Pistons 3 and 4 scared me to bone, but compression test follows...
What I found out on testdrive is that I got more backfire with new spark plugs, and I can hear pumping hiss from passanger side when under WOT (was there before but not so noticable), or low RPM push. Exhaust manifold or gasket leak could be a real cause of 41, not vacuum leak??! Possible?
Would it cause rough idle also?
Passanger side still 41 (lean), but I must check mentioned exhaust for leak. I learned nothing from vacuum leak. Blocked all hoses, no change, neither slight. For test I made vacuum leak intentionally, and it was obvious. Either under manifolds or not existing, must borrow dial for vacuum. After my PCV fix, sucking really well.
Tomorrow we will do a good compression test.
Have a Nice afternoon all!
Anyways, I done like dozen of Cylinder Balance Test and every time I get 9 9.
Done something this weekend.
I changed sparkplugs from Motorcraft 42 to NGK UR45. Old sparkplugs by the book, perfect... Picture attached.
Inspected all pistons. See attached pictures, seems to me like carbon buildup. I hope so. Getting worse to back of engine. Clogged PCV may contributed this buildup...dunno if PO knew that. I am a little bit worried, Pistons 3 and 4 scared me to bone, but compression test follows...
What I found out on testdrive is that I got more backfire with new spark plugs, and I can hear pumping hiss from passanger side when under WOT (was there before but not so noticable), or low RPM push. Exhaust manifold or gasket leak could be a real cause of 41, not vacuum leak??! Possible?
Would it cause rough idle also?
Passanger side still 41 (lean), but I must check mentioned exhaust for leak. I learned nothing from vacuum leak. Blocked all hoses, no change, neither slight. For test I made vacuum leak intentionally, and it was obvious. Either under manifolds or not existing, must borrow dial for vacuum. After my PCV fix, sucking really well.
Tomorrow we will do a good compression test.
Have a Nice afternoon all!