Getting high revs before shifting and I started looking into the vacuum lines. The lines looks good and I got a reading of 17hg and bouncing needle near the brake booster. I went further back to the vacuum pump and it does seem to be pulsing coming from the check valve on the pump with an erratic reading. Is this a sign of pump failure or bad valve? I'm going to pull the valve as soon as I find my 22mm socket...