O.k Frank, we will do what you said, next time we are with the car...unfortunately it is stuck at a friends shop where the cam was changed. We pulled a couple plugs and checked for spark...we were getting spark at those we pulled. They did spark sitting connected against a part of the engine in the open where we could see....whether it is good enough spark??? Also took the cap off and cleaned it and the rotor. The plugs we did pull looked slightly wet when we initially pulled them from the engine after it ran briefly, following the cam change?

My friend posed the question of camshaft compatability. He was wodering if they used slightly different cams for these m116 engines, from year to year. He was worried that maybe that replacement cam was perhaps not allowing the valves to close completely. The car we are working on is an 1988 420sel, and I am nearly certain the replacement cam came from a 1987/1988 or 1989 420 sel. Not sure if it makes a difference.

I should also mention that we had a complete cylinder head with us that we took the replacement cam and followers from. We noticed a couple of lifters (things screwed into the head with balls on the end) had collappsed on the car in qusetion so we changed them out with some good ones from the parts head.

One of the collappsed lifters actually came apart by pulling the ball part out...to reveal a spring and a check ball.