well i compression tested my 87 TII tonight because it dosnt run to good, not to bad but it has trouble starting and in idle. I got nothing over 60psi on the front rotor and nothing over 30 psi on the back. I tested it like 4 times just to make sure, and thats what i keep getting. I have never compression tested anything before but it seemed pretty easy. (i did take the valve stem out of my compression tester) anyway i didnt think the car would even run if the numbers were that low haha am i messing anything up?? anyone got any ideas?

 

Is the throttle wide open? Did you pull the egi fuse? But it sounds like it's hurting with a 50% difference.

 

Yea make sure you hold the throttle wide open and I'd disconnect your crank angle sensor and pull the fuse for the fuel injectors. You shouldn't have to take the valve core out of the tester. Also make sure that you crank the engine over for seven pulses or until the gage hits its maximum reading.

 

which valve did you remove?..look up www.rotaryresurrection.com there is a link on Compression testing.

 

haha well i tried all that stuff and i looked at that compression testing info but i still got the same. 60 on all sides on the front rotor but on the back one i got two pulses at 15 and then a big one at 30 haha i read that that could mean i have a blown side seal in the back rotor. thats probly true the car is old. The car still runs its just a pain to get started once its warm it seems to run okay...kinda but it dosent smoke so that seems odd to me. i pulled that little valve stem out of the compression tester the one that makes the gauge hold the compression reading when you test a piston engine. i think it needs to be rebuilt saddly but it does have 160k on it

 

Try it with the Valve out.Then Try it again with the Valve IN..with the Valve IN,it will Tell you the Overall Highest Compression...now,doing it with the valve out,lets you hear the pulses of the Rotor,and gives you an idea of the Face compression..But Nothing beats a Mazda tester if you can Get a hold of one.