>>>Edward M. De Reyes said:
> compression check [...]
>
> 3) Remove the coil wire from the distributor cap to keep the motor
> from starting.
I'd STRONGLY urge removing the low-tension lead from the coil; if you just
remove the high-tension coil lead you will still get sparks (just not in the
plugs) and you may have gas and air mixture spewing out of the open spark plug
holes.
> 6) I don't have the exact factory settings for the compression, but I seem
> to recall a reading of about 120 or 125 psi to be about right. You might
> want to check this figure, though.
To a first approximation, take your compression ration and multiply by 15.
Atmospheric pressure is about 15 PSI (14.8 is "normal"), so for a 10:1 ratio,
you should see close to 150 PSI. For an older lower compresion engine (like
my Mk VI Bentley's 6.75:1) you'd see about 100PSI. Now, no engine's seals are
ever perfect, so you'll see less than that, but don't worry unless it's a lot
less.
Also, what you REALLY want to see is a uniform series of numbers, like
130 135 130 125 135 130
without a lot of variation; if you see one number way low:
130 135 80 125 135 130
then that cylinder has a big problem.
--berry
Berry Kercheval :: kerch@parc.xerox.com :: Xerox Palo Alto Research Center
|