My engine hesitates when accelerating when it is cold and humid out, especially if raining. The problem stops once the engine warms up. Any ideas?

 

Without having a clue as to what you are driving, I will suggest removing the distributor cap and looking at the base plate. If there is a small screen or opening there it can become clogged with debris and trap moisture that can cause the symptoms you've described.

 

And while you have the cap off, take some fine emory cloth or sandpaper and clean up the corrossion I'm sure you'll find on the contacts. Make sure you clean up the button and rotor, too.

 

Its a 2000 Blazer LS

 

And the SES lite isnt coming on? Bet it is..
Also can be plug wires are worn out. Do the cap rotor wires..Ac Delco is best.

Dont buy cheap, unless you like coming back here and doing humble pie for not listening to us.
Happens over and over. It's embarrassing.

BTW: What did the clutch problem turn out to be?

 

Cap and rotor! Definately. Just went through this myself. Shoot the wad and buy delphi/ delco. I bought a cheapy wells and got 10k out of them before the crudded up. Talked to a Napa guy and this is a common prob. And GM knows about it.

 

Thanks guys. Ill give that a try. As for the clutch, the slave and master cylinders were blown. No, the SES lite has not came on.

 

GM knows about what - that making electrical parts that cause your engine to run correctly is the right way to do it? We have always explained that folks buying electrical parts (including fuel pumps) for these engines should get AC/Delco or Delphi.

 

GM knows that there was a flaw in the original design of the distributer during these years resulting in excessive moisture inside the cap. The replacement had been redesigned to prevent the build up of excessive moisture. That is provided you buy the ACDelco brand.

*UPDATE* After a little research turns out there was no "redesign" Found the TSB that simply says to blow out the vents on the Base of the distributer. Just goes to show you that most parts guys are FOS. And I, unfortunately, got sucked in.