Compression test

[tima01864]

I have never done a compression test, surprising to me. Any tips on a fuel injected engine?

[RRoller123]

Unplug the AFM so that it doesn't spray fuel and possibly flood the engine (on my '80, the engine will still turn over with the AFM unplugged). Unplug the CSI just in case. Not sure, but I think it will fire regardless of the AFM activity while cranking.

Pull all 4 plugs at the same time, so any break between cylinders will not be masked.

Pull the big air hose off and prop open the throttle plate fully somehow, either a small block of wood or something that won't scratch or leave debris, or hold down the throttle pedal fully, or clamp the cable, etc etc. The idea is to eliminate all possible air inflow restrictions.

With a screw-in type compression gauge, you can just hold down the throttle pedal while you crank the engine.

Pete