rx7 SE

iTrader: (5)

Ok, my tII is starting to worry me. Yesterday i did a compression test because my coolant is disappearing too fast so i did and it kept good under pressure like a pro. But when i did a compression test i few things were ify. For one, the chamber that had the highest compression (85 psi) had a rusted spark plug. Then the chamber right below it with a good spark plug had a compression of 35 psi, but the needle consistantly bounced. I didn't have time to check all four, but the third chamber had 83psi. The engine only has about 7300 miles on it, and it was professionally rebuilt from (can't think of the name right now) some place. What do you think is wrong?

SureShot

COPMRESSION TEST
Leading (bottom) plugs in, trailing (top) plugs out, EGI fuse out (to cut off fuel).
If the engine has been sitting for a while, spray some WD40 in the trailing holes on all rotor faces to free up any stuck seals & build compression.
Install the tester in a trailing hole & crank the engine at WOT.
Here is the tricky part.
Open the bleed valve on the tester enough to see the needle bounce up & down between each face.
Observe the sets of three pressure peaks.
100's - good
90's - OK
80's - about worn out
My J-spec shows 87-87-87 front & 85-85-85 rear.
My hurt A-spec was 85-85-83 front & 80-50-50 rear.
Then let the bleed valve close & see what the max pressure builds up to. It’s usually 15-20 PSI higher. Which is closer to what an electronic tester will show.