Good compression test readings?(got a low cylinder)NEED HELP

I had water bad [half full] in one of the spark plug holes producing a miss after the car was parked awhile and vehicle had experienced a large driving rainstorm that washed into the engine bay via the air scoop. Drying the leads off got it running smooth again with no spark miss.
But, unfortunately with the low 120 compression in one cyl you could be needing to test wet with oil and have a leak down test done to further isolate the problem. Best luck.

what do you mean by a leak down test, I have heard it before but dont know what it consists of? Do I need special tools? What does it cost for a shop to do one. By the sounds of it,it could really narrow down what is actually wrong

For a leak down test wikipedia has a diagram and explains a bit:
"Compression testing is a crude form of leak-down testing which also includes effects due to compression ratio, starter/battery condition and other factors. Leak-down testing confines the results to cylinder leakage alone."
http://en.wikipedia.org/wiki/Leak-down_tester
There' a schematic that might be duplicated or diy perhaps. Sorry no idea on costs for the test but it would help elimnate variables.
For gtir specific procedures here's as an online ref that is useful: http://www.gtirworkshopmanual.com/default.aspx?v=1

also both factory manuals in pdf format are seen here recently.

http://pdfdatabase.com/nissan-pulsar-gtir-n14-service-manual.html

You have been a great help thank you so much. I just came in from pulling off the valve cover,removed plugs cranked it over and discovered that the oiler lines obove the cam shafts are not pumping oil,the lobes on the camshafts that drive # 1&2 cylinders are severly heat damaged,and worn quite bad due to the size of the ridge on each side of the lobe on the camshafts.If the top end looks like this,what does the bottom end look like?Having a comp. reading of 160 to me that even seems a little low.(180-200)is what my old civic had.Im starting to think I should be looking for another motor to drop into this car.

welcome and good luck with swap/rebuild as may result. 160 is good. Hopefully just the top end and figuring the oiling issue will be all. best success

same here, im 150 120 (got back up to 150 with oil) 145 145 . . . also I am hearing valve knocking ... could this be related ?

Stock compression is 165 across the board, It's an 8.3-1 engine

After adding a couple drops of oil to # 1 cylinder my reading went from 120ish to almost 160,I have searched around and found that I am not the only 1 with 120psi on #1 cylinder.Why only 1 cylinder?Why wouldnt all cylinders come down in compression,are the rnn14 sr20's known for more heat build-up on the belt side of the motor?I had a problem with my camshaft oil lines being plugged(every little hole on those lines were plugged)but that is the top end of the motor.Can someone tell me if they had this same problem with 1 cylinder being low?If so is there anything else it could be other than bad rings(maybe a slightly warped valve)Is it possible that it could be a head gasket without any visual signs(no antifreeze in oil, no anti-freeze in the exhaust,and there is no oil in the anti-freeze)