no compression on all cylinders!

[chet]

I am not getting anything. I have not had time to touch it this week. I am going to play with it this weekend and see what I get. Hopefully something!

[Master ACiD]

i vote for a bad compression tester. i have had 3 go bad personally. and my dad has 2 bad ones as well. ours were all cheap ass made in china pieces.

[chrissev]

true.  would depend how long you waited though.  You'd get an initial 45psi but if you waited any time at all it would go down to zero.  If he's cranking it over, then looking at the gauge and the gauge goes down to zero very quickly then stays there, he'd think he had no compression but he would actually have a small amount for a small period of time till the air leaked out.

Well, that's not quite right.  The pressure is supposed to be kept in the gauge by a check valve in a properly functioning gauge.  If what you are saying were true, no compression gauge would read anything except zero as soon as the exhaust valve opened right after the power stroke.  The fact is that with a properly functioning gauge, the needle moves up as the gauge line and adapter are filled with pressurized air.  The gauge stops moving up when it is equal to the maximum pressure achieved in the cylinder.  The gauge does not drop back to zero until the shrader valve is opened releasing the pressure.  If careful one could actually remove the gauge and adapter from the engine as a unit without releasing the pressure and it would still register on the gauge independant of the engine.

There is a good likelyhood that his gauge is faulty.  There is also a good likelyhood that he has zero compression.

Andrew

That is IF he's using an actual compression testing gauge.  I personally use a PSI gauge attached to the body of a fuel injector.  It doesn't have a check valve.