Whats the best spark plug?

[LI99HOE]

Update: In looking under the hood @ night, I notice a little bit of a lightning show while the truck is idling right where the Spark plug wire boots connect to the spark plugs. Anyone else run into this after doing a tune-up on one of these?
I'm thinking this may have something to do with my misfire code.

What I have installed
Ac Delco 41-993's gap set @ .060
Bosch Premium wire set
Duralast Gold cap/rotor (brass contacts)

 

[SunlitComet]

Is is exactly what has to do with your misfiring code. Dump the bosch wires and use acdelco 9718q's or msd's 32169. It sound like weak wire insulation or cracked plug insulators. That is where and why you are misfiring. You should not see any light show at all.

 

[LI99HOE]

Thanx for the info Sun.... I'll pick up new wires/plugs, and install 'em....again...lol..... and report the results.

 

[SunlitComet]

you should be able to keep your plugs just try wires first if the misfiring is still there replace that individual plug.

 

[ChiTahoe]

As old as this post is, I'm running NGK Iridium IX, no real difference just brought the truck back to stock performance. I pulled out the AC Delcos at 160K. Installed new spider unit, replaced lower intake mani gaskets, replaced cap, rotor, wires. I think now I just need to clean the injectors to bring back the silk smooth idle. (That anti corrosion gel is prolly still on them) I also run premium gas.

 

[LI99HOE]

@ ChiTahoe....... when you bought the NGK iridiums, was the gap set to factory .060, or did they close 'em up a bit?
I was going to get the Iridiums @ one point, but the pre-set gap was .051, and I wasn't sure if that was good for my OBS '99 Tahoe.
I noticed you got a '97...got any pics?
As far as cleaning injectors, I shock the system with Techron, and mostly run 89 octane.

 

[LI99HOE]

Would anyone happen to have part#'s for the spark plug heat shields? I've got one that broke right where it bolts to the engine.
Of course in doing plugs/wires, I must have moved it a bit, and now the rattle is annoying.
I know that removing it, and welding the tab back, or getting one from a junker would do, but new would last a lot longer.

 

[SunlitComet]

12551505

 

[LI99HOE]

@ Sun...thnx for the part# again...lol.... where do you get 'em??
I put the new plugs, along with OEM wires, and gobs of Di-electric grease in the boots.
No more arcing, and the idle/power band is smoother.
As far as the spark plug heat shield..... I realized that the exhaust manifold bolts have to be removed to change it.....sooooo.... I JB Welded the broken side for now.
It's a cheesey repair, but maybe better than opening a can of worms.

 

[SunlitComet]

any local dealer near you. Removing the bolts is a touchy subject, when I took my heads off I found three bolts broken in heads but absolutely no existing leaks or any signs of problems.