Hello, I need to fix my recently bought 960 3.0. I bought it as a non-runner, stood for more than a year, now it runs fine, but on 5 cylinders. The no1. cylinder has zero compression when cranking. All the others are fine (170 psi) and even, just this one. I measured the compression at idle too, it was reading 110 ps. I changed the oil to quality synthetic type which eliminated the tappet noise. What options do I have now?
1) Drop the head and inspect the valves and guides?
2) Do an Italian tune-up? (up to redline in low gear)
Maybe it's just a sticking valve or two? Or some carbon deposit around the exhaust valve? If I drive it around in low gear/high rpm for a while, should I pull the injector's connector to avoid the overflood situation at the non-working cylinder?
Thanks for the help, I'm new at Volvos, but I really like this one.

Wal