Expert: Skip Bollinger - 5/19/2007

Question
Hi. I have a question concerning a 1997 S10 Blazer 4.3 4x2... it has a hesitation problem at idle or in drive at a stop sign.  Occasionally this hesitation happens at full speed.  It reeks of a mass air/fuel system problem or throttle body.  I am thinking TBI/ mass air flow sensor but am open to your ideas and hope to draw on everyone's ideas and your expertise.  Thanks, Charles.  

Answer
Charles,
  As I learned in Auto Mechanics 100, check the tune up on the vehicle. Also check to see the engine is in tuneable condition meaning make sure there is sufficient compression to make the thing go smoothly.  
  When was the last time it was tuned up? Did they replace the spark plugs? Did they replace the wires, cap and rotor?
  This thing is 10 years old and there could be a lot of possible problems. To me, it does not seem to be an MAF or fuel problem. IF it were, it would be happening all the time, not just sporadically.
  If I were you, I'd take a plant mister, in the dark, and spray the spark plug wires to see if you see any arcking between the wires. IF you do, just do a good tune up on the truck. IF you don't, I'd take a good look at the distributor cap. Look at the inside at the contacts. See if there are any lines between the contacts that look like a pencil line. This is called "carbon tracking".
  I hope this helps a bit. Please remember, in my Profile, I'm a Parts Specialist, NOT a Tech. I don't know squat about late model vehicles but I hope this helps..
Skip