whats it need? its a 91 ej22 low comp one cylinder?

valves or rings check for smoke out of oil cap when runing or uneveness out of exhaust

Do a leakdown w/ compressed air.

 

If you can hear air wooshing out a valve, either inatke or exhaust, you can pull heads and replace valve.

 

If the air leaks into the crankcase, you've got ring issues.....probably better to look for a new shortblock. Toss that case aside for a rebuild later.

You can do a leakdown or you can put a few squirts of oil in the cylinder and retest. If it's rings the reading will shoot way up. If it's valves it may go up a little but not to 185 where it should be.

 

GD