how to test compression - LS1

having a misfire problem following each 4k rpm or higher run...

have already checked plugs, wires, coils, injectors, flushed oil and added fuel cleaner.

thinnking it is a weak valve spring or bad lifter....

hoping a compression check will show something.

how do i check it? pull the fuel pump fuse and just crank the engine with the plug out?

or is there another way?

:D Don't know, but make sure your car will not start during cranking and be sure you block the throddle wide open during the test so the car get's air. :D

what if i disconnect the coil pack connectors? this way none of the cylinders get spark.

somebody has to have tested compression on an LS1 in here!!

This (http://shbox.com/1/4th_gen_tech2.html#compression_test) was written for the LT1, but should still work for you. Maybe a minor change or two.

i should have known you had a writeup on it :thumb:

said it once and i'll say it again....shoebox you are "the man"