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Like Kyle said, with a few additions:
the remote starter connection is usually found behind the intake manifold at the firewall - a single female spade terminal. Jumper it to the battery pos. terminal to crank the engine. Since the key is off, the fuel pumps won't run. But due to the ballast resistor ignition setup, you will get spark at the coil while cranking, so disconnect the #15 coil terminal.
Block the throttle about 1/4 open (or more) to let air flow into the test cylinder. Warm-to-hot engine is best, it simulates operating conditions.
Screw-in gauge is preferred. Good cylinders should come up to 99% of final pressure in three strokes: 75%-95%-99%..then the needle will just flicker on subsequent strokes.
Main thing is that all cylinders are fairly close, say within 20psi. Should all be around 140-170 psi depending on mileage and wear. One bad cylinder? - almost always points to a leaking valve, usually the exhaust. If all cylinders are low, but fairly even, it suggests worn rings. At that point a "wet" test may be worthwhile to confirm. Squirt a couple of cc's of oil in there, trying to get it to the high side of the piston (intake side) so it can run down and "seal" the rings all around. Put a rag over the oiled cyl plug hole and crank the engine a few turns - oil will spray out. Then do your test. Good cyl's will come up a little, ones with bad rings, maybe a lot.
I've tried leakdown testing - great in theory, but I found them very time-consuming and hard to perform correctly, and results were quite variable and didn't add much useful info to a good compression test. Maybe just my lack of skill.
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Bob (son's 81-244GL B21F, dtr's 83-244DL B23F, 'my' 94-944 B230FD; plus grocery-getter Dodge minivan, hobbycar MGB, and numerous old motorcycles)
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