I'm watching Scotty Kilmer on YouTube, talking about checking out used cars.
He hooked up a compression tester to check the compression, then said a quick and dirty way of checking was to get a multimeter with an amp clamp. Set the meter to auto-display, take out the fuel injection fuse, connect the clamp to the negative lead. Turn the car over and watch the voltage spikes on the meter display. As the starter turns the engine, the graph spikes as the starter draws power.
If a cylinder has bad compression, it'll take less power to turn the engine, which will show up on the meter as a lower spike.
Crude, but effective - especially if you're looking to decide on a car, not fix it.
--- SBBSecho 3.11-Win32
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