Just performed a compression test on my 1968 220D, but I realized that I might have done it slightly wrong. (all were 360 -390 psi via the glowplug hole, using the method I am about the describe).

I let the engine crank until the pressure no longer rose on the pressure gauge. But afterwards, I noticed that both the FSM for my car and the fine instructions in my Harbor Freight compression tester indicate I should only "crank the engine by 8 revolutions...".

So 8 revolutions at the crank is only 4 compressions of the cylinder in question (I think), so which of these three options is correct:

1) Crank the engine until the pressure no longer rises on that cylinder (maybe 12 compressions or so)
2) Crank the engine so 8 compressions occur on that cylinder
3) Crank the engine so 4 compressions occur on that cylinder

Thanks, and sorry if this seems like a dumb question. But it is hard to make sense of the FSM's 22-24 bar (319-350 psi) unless I know exactly how much to crank the engine. If it is option 3, my engine has low compression (maybe 200 psi). If it is option 2, my engine has mediocre compression (maybe 300 psi). If it is option 1, my engine has pretty good compression (the 360-390 mentioned above).