Low vacuum and compression 2.25L ???

[mongoswede]

ok, we have established that said or not said beer is supposed to be there. but i do compression test just a bit different than daveb. i remove all spark plugs and from daveb instructions i get the impression he has the 3 non testing at the time cylinders' spark plugs in

so is it all out or just one out at a time?

pull one spark plug at a time. The readings should be similar in either scenario but I have always left the plugs in.

[4flattires]

Test performed...

...with plugs removed.

Primarily due to keeping the cranking speed up for the duration of the test (battery drain). Remember some cars on the road are V8's.

Secondarily due to keeping the cranking RPMs higher without plugs vs with plugs.

Thirdly because it is too dang tiresome pulling, replacing, pulling, replacing, etc. Pull 'em all at once. Replace 'em all at once.

Most importantly, keep one hand handy for the tester, the other hand firmly on the pint when yelling....crank it!

[bkreutz]

If you want a really accurate test, do a leakdown test (or have someone do it) That way if you have excessive leakdown it will pinpoint where the loss is (intake/exhaust/rings) That's the method I use if I have a concern about compression.

[daveb]

Plugs in or out shouldn't matter too much unless you have a weak battery or starter circuit. In which case you should sort that as well. For the less mechanically inlcined removing the plugs one at a time will save hassle getting the wires back on in the correct order. Hence my decision to suggest that method.

I usually pull them all too, FWIW.