i recently did a compression check with it being 175-180 across on my 1995 s14 240sx because i was getting smoke coming out of my exhaust when i leave a stop light or stop sign and it dissipates and doesn't smoke until i sit at a light or take off only when sitting. this is the reason i did a compression check. I also have an issue with starting sometimes and the symptom is it starts fine sometimes and other times it takes 2-4 seconds longer to fire up, - thus being another reason to check the condition of my cylinders.I have been running 93 octane for a while now. i did the compression check with removing spark plug wires and next plugs. after all of them were removed i checked the compression of each cylinder. i kept the plugs in the correct order and replaced them in the correct spot of which they came out of since the compression was good. i waited like 10 min. to let the fumes clear out of the cylinders to crank it over and it wont start.