I have a 96 S10 2wd 4.3L auto that has starting problems. The problem is when you turn the key to crank the truck the motor is turning over and sometimes it cranks immediately then sometimes it may take 2,3,4,5,6,7,8 seconds to crank or not crank at all, but when you turn the key back then try to crank again it starts immediately. Battery has been load tested. The alternator has been tested and the starter and solenoid have been tested. any help would be appreciated?