Dear JB,
    My car is a 1998 Buick Regal with around 45,000 miles on it.  I bought it new and have always had it maintained by my local dealer.  Here's my problem:  it now has begun to idle too fast, the exhaust smells like rotten eggs and my fuel mileage has dropped significantly.  Does it need a tune-up or something?
Blue Buick Bob

Dear Blue,
    It might need a tune-up, but it is unlikely to fix your problem.  I think your trouble lies with a part known as the engine coolant temperature sensor.  You see, Bob, all engines need fuel and air in order to run.  Cold engines need more air and more fuel than normal because they aren't very efficient until they warm up and therefore will be prone to stall.  An older car would have had a choke on the carburetor to accomplish this, but in the electronic age we just let the computer do it for us.  The computer is always listening to the coolant sensor to

determine fuel trim and your sensor is lying.  In other words it is always telling the computer, "It's cold down here!" when in fact the engine is warm.  The computer continues to add the extra fuel and air even though the engine doesn't need it and that's what is causing your neighbors to say, "Here comes ol' Stinky" whenever they see you driving down the street.

Dear JB,
    I have two problems.  First let me say that I love "Martha" my 1977 Dodge Aspen, and if you tell me to get rid of her I will never speak to you again (since I've never spoken with you at all I guess that wouldn't be any great loss to you).  I got her in college and she has served me well.  Now that she is relegated to the status of the third string backup for my family she sits most of the time. 
    While driving at night sometimes the headlights will suddenly go out.  As I frantically work the light switch, pound the dashboard and stomp the dimmer switch on the floor they will magically turn themselves back on as if nothing ever happened.  The other problem is related to the lights (I think) in that anytime I am idling her at a traffic light at night all the lights including her dashboard illuminators will "pulsate" rapidly from dim to bright.  Please help poor Martha.  I can't bear to think of parting with her.  By the way, keep it cheap.
Martha's Mommy

Dear MM,
    Oh for the days of yesteryear when the likes of Martha would serenade us with Steve and Edie on a hi-fidelity eight track tape player.  Now on to more pressing matters, like your lights.  The two problems aren't related.  The first is a current flow problem.  The dimmer switch is the most likely culprit here since it is mounted on the floor and is subjected to a lot of moisture, spilled coffee, etc.  Another thing to check is the ground wire on the headlights.  It may be loose or corroded.  As to your second complaint you may have given some insight to the solution

when you mentioned that it (I'm sorry, SHE) sits a lot.  I suspect that the battery voltage is lower than it should be and that you are seeing the alternator at work while sitting at a traffic light.  Have the battery checked, it probably needs to be replaced. 

JB can be seen each Thursday morning on WDEF-TV News 12's Morning Show at 7:30 A.M. where he answers your car questions.  He can also be heard Saturday Mornings 7-9 on Talk Radio 102.3 FM on the Saturday Morning Garage.  He spends the rest of his time taking advantage of helpless motorists at North Shore Auto Repair in Chattanooga.  E-mail JB at jeepster1515@yahoo.com to have your car care question answered in this column.