Driving to work tonight in my 97,driving rain,which is the reason I chose this vehicle tonight. After about 20 miles I experienced a "whump" and the engine quit at 50 mph-immediately threw it into neutral and it restarted instantly and I went on my way.After the rain quit I checked for loose air intake issues. None. I did not hit a puddle to cause an engine quit as the "whump" was an engine noise,not a severe hitting of deep water at high speed.I have since put almost 50 more miles on it. One thought is maybe a carbon build up breaking free? I feel this is unlikely due to the fact I use MMO EVERY tank and the ethanol is so high detergent. No CEL or drivability problems; Wierd. Any ideas?

 

Thinking impure thoughts?

97 you most likely have a new ignition switch by now.