B16A Cylinder Pressure

[utn]

Ok so I did a compression test a few days ago and these were my results.

Cylinder #4: 80 PSI A lot of black oily soot on spark plugs.
Cylinder #3: 65 PSI A lot of black oily soot on spark plugs.
Cylinder #2: 150 PSI Normal looking plugs
Cylinder #1: 190 PSI Normal looking plugs

I'm aware that 80 and 65 PSI is horribly bad and there is something seriously wrong, like damaged piston rings etc. but whats up with cylinder #1? Why did I get 190 PSI? I thought B16As were supposed to be about 140-160 PSI. Could this mean that I either dont have a completely stock engine or that there is something else wrong, like excessive carbon build up?

Thanks,
Scott

 

[posol]

there's no set figure for this, and not all compression gauges are the same. it's not so much the numbers that matter as the difference between each cyl. as you suspected, something is fubar on 3 and 4. 2 might have small issues going on too.

try dropping a bit of oil down the spark plug tube on #2 and do it again.
if it shoots up to match #1, you got something going on...

try doing a leak-down test as well.