that would cause poor compression. more likely it's a fuel delivery problem...fuel pump, injectors, clogged fuel filter or possibly an ignition issue...bad plugs, bad distributor, spark plug wires. if you suspect the mechanic is a fraud get a second opinion.
hard to diagnose without some more details. does the starter spin but the engine doesn't fire. are the spark plugs covered with gunk, have they ever been changed?
_________________
'68 gray 2002 pig-cheeker - '74 verona 2002 - '74 turkis 2002ti(-i) project - '97 Ford Ranger parts hauler - '06 astro black MINI Cooper