What brand cap rotor and plugs? these trucks only like acdelco. Also they are gapped right out of the box. Iridium plugs have an Iridium tip on them that can be broken off messing things up

 

What year is yours? I thought the plug gap for all 2nd gen 4.3L (VIN engine code W or X) was 0.045".

Plugs should be AC-Delco 41-932 (Iridium, change every 100,000 miles). Some will tell you those plugs and no others. For me, if you're on a budget, but religious about changing them, AC-Delco R44LTS6 will perform adequately (copper electrode, inspect/regap at 15,000 miles, change at 30,000 miles). Like many GM engines, these run poorly with spark plugs from other sources.

Wires need to be good quality. AC-Delco exact fit wires are expensive, but probably worth it for iridium plugs. I'm not a fan of the AC-Delco "Professional" wires. Delphi also makes good wires for these engines. Avoid "house brand" wires, especially with iridium plugs. With copper plugs, the wires don't have to last 100K miles, so slightly lesser wires will work OK, provided you change them when you change plugs. My experience is that Denso wires work well with the copper plugs.

Dizzy cap and rotor need to be AC-Delco, no substitutes.

 

Pretty sure all are .060

 

it's a 2001 Jimmy
I only buy AC Delco, cap/rotor and #14 plugs
I was just wondering because my motor manual and the emissions sticker both say .060, but the plugs I took out were gaped .045; didn't know if I was missing out on a "trick" other blazer owners knew about that I didn't.

 

I just checked and yours should be 0.060" gap for the plugs.

I'm not sure when it changed. The owner's manual and the factory service info on my 1996 says 0.045".

 

AC Delco 41-933 with a gap of .060

 

Is that for the 2001? Or for all years?

My hard copy owners manual says 0.045" for my 1996, and the online factory info I can get at the library for the 1996 model agrees with that. My emissions sticker on the fan shroud says 0.060", but the upper fan shroud has a distinct "not original" look (paint pen stock # from a junk yard, and another GM sticker that I know didn't exist in 1996). My fan blades also have the same paint pen stock # on them, and the lower shroud was damaged when I got the thing.

 

Pretty sure 96 & 97 are the same. 98, and newer use 41-933 plugs with a .060 gap.

 

Okay figured it out, one of the plug boots came off the wire.
Couldn't see myself dishing out $100 for AC Delco wires, got some Summit Racing ones, which by the way the summit tech guy said are MSD wires in a summit box, still has MSD labeling on the wires.
Left the plugs @ .0600, everything is running great now.

Thank you to everyone for your help, it is greatly appreciated.

 

Where are you buying wires at? Rock Auto has AC Delco wire sets for about $35.