I have a 1993 jeep gran cherokee with a 5.2 v-8. when i bought it it was slow starting but always fired just took a little bit. Its been running fine. then recently refused to start. then stared like the next day with alot of turning over. then it ran fine. i checked my fuel filter its good. im getting plenty of fuel. I pulled my spark plug wire off of one plug. i have spark. ive heard of the crankshaft sensor being a jeep problem. could that be it. please help.