low ldle,low compression in 1 cyl,causes?

[rcgtsport]

to keep short cel came on, scanned missfire in 2,4. car idled low when warm.changed cap,rotor left work died on way home no spark.after test changed coil fired back up but still low idle. so change plugs no luck. did commresion test because i have that tool and heard puffing out exaust pipe. found compesion to be from drivers side in to be 160,90,165,150. could this be bad injector,loose valve. took oil fill off and little presure but not enough to blow cap off when turned upside down. dont have fuel pressure gauge should i bother picking one up? i have 96 civic ex

[90 Civic]

You might try adjusting the valves & see if the compression changes. Low Compression is valve or piston rings. You can squirt a few drops of oil in the low cylinder & see if it raises the compression. If it does them there is a good chance of a bad compression ring.

[mk378]

Valves set too tight will not close completely causing loss of compression. So loosen up all the valves on that cylinder (don't have to set to anything exact, just loose) and test again. Then do the oil test if compression is still low. Cylinder 2 is the one you measured low. The cylinder closest to the timing belt is #1.

[rcgtsport]

thanks for the info i tried loosening valves didnt help. then i adjusted valves and gained about 5 to 10 pounds exept in the one cyl. so i put 2 cap full of oil and it raised from 90 to 120. still low idle at a stop waiting to get it scanned again to see if idle controle mod. is screwed up. what you opion on low cyl let it go or find someone to re ring cyl dont hear of that any more.