Yeah you read that right folks!

So my blazer seems to idle really badly almost every time after a car wash after being in neutral, but returns to normal if the rpms go to 3,000 or more. It stutters between 400 rpm and 900. Normally it sits at 600. It starts in the car wash once I start moving in neutral, and when I put it into drive it just doesn't stop until I bring up the rpms. When it happens it feels like a misfire, but no code comes up. It runs fine day to day driving though. What is going on here?!

 

Needs an AC Delco distributor cap & rotor, and possibly spark plug wires.

 

The wires and rotor are fairly new, but the cap is idk how old, but the contact points have white carbon on them.

 

The white residue is supposed to be there. It is crystalized silicone dielectric grease. It's on there to slow the corrosion process on the aluminum contacts. Make sure you install an AC Delco cap, aftermarket caps are junk and they don't last. Put a dab of the grease on each terminal, inside and out, of the cap before you install it.

 

That makes sense, I thought that was white carbon. I think it's the original cap. After all it went 16 years with original plugs and wires before a tune up..., which I did myself, and didn't include a new cap... I can't recall the cap ever being replaced by a shop either. I'll mention this to my mechanic next time I need an oil change. Thanks!

 

Don't go cheap on the cap, AC Delco only. You'd be hard pressed to get 2 years on an aftermarket cap.