Here is the deal. I have a 2WD 1998 Astro. 77,000 miles. This morning I went out to start it and it cranked and cranked but it wouldn't start. I called mechanic and he wants $400 to replace spark plugs, wires, distributor cap and rotor, ignition coil, PCV valve. This hasn't been done on my car. My question is this, wouldn't I have had rough idling or trouble starting if these things were going bad? Also is it hard to do these things myself? I don't know were the spark plugs are. I think the distributor is behind the center console. Any suggestions would be greatly appreciated. Thanks