People that owned Rav4 blew the Head gasket, then let it sit up for a year. When we got the car, the motor was seized. We got it unseized and had the motor turned down and have put it partually back together. The spark plugs that we pulled off were rusted so we replaced them, now the car tries to crank, but the spark plugs are not firing. What can we trouble shoot to try to get them to work.