Recently purchased the car knowing that it was low compression on number 7. The first diagnosis was a cracked piston. Started to get the left head off with the motor in place. Got the with the corner against the firewall so I pulled the engine out. Piston good, head gasket good,rings good. Finally found a pimple of metal on the exhaust valve seat.
Working on a phone here and pushed the wrong button. Anyway the motor is back together and running. As I stated the motor revs up to 2000 for a couple of seconds and then drops back down to 1000 rpm. Could I have missed a connection or will I have to pull off the intake manifold to seal vacuum leaks?