88PatrolCar

Sounds like you have a burnt up valve, a broken valve spring or a piece of carbon is hanging up and keeping a valve from closing. Do a dry compression test and write down all of the results on a piece of paper. 125psi is about the lowest you want to go. If you find a low one then do a wet compression test on this cylinder by pouring a little oil down in the cylinder this helps seat the rings, if the pressure is still low then it is a valve, if it raises up a good amount then you have worn rings. Hope this helps!