Checker auto parts told me I have no egr valve on my 93 ciera (3.3L) and after looking and looking I agree. Probably and igniton spark issue. Namely the harmonic balancer and crankshaft sensor. This is a messy repair which is very hard to do yourself and the tools are very expensive. See page 2-15 in your chilton manual. The j-37089 tool is ($342) and a 3 jaw puller is $50
I am going thru the samething and here is what I have come up with: the sensor is $42 and a new harmonic balancer is $80-99 and the labor at my local dealership is only and hour and a half so $170 worst case i will spend around $330 and ill have new sensor, balancer installed for less then a j-37089 crankshaft sensor checker tool alone costs.