The engine is worn out. It needs to be rebuilt. The 90 PSI is very low, 155 PSI is normal, and the 0 PSI concerns me. It could be a bent or stuck valve, a hole in the piston. You need to pull the head off to check for the cause.
Let me know what you find and we'll go from there.
Sunday, March 22nd, 2009 AT 1:45 PM