Alright guys.. changed my spark plugs to NGK TR55's.. Chevy says gap them at .060 so thats what i did.. That is could be my mistake but im not sure.. I fire up my truck and it seems like its idleing fine.. Well i took for a drive and heres were the problems start.. Once i get over like 3k it sounds like im getting knock... the truck still pulls but it sounds weird and doesnt pull as hard as it used to.. Also if im in overdrive or trying to get on the interstate driving easy i get a violent shake at about 60 all the way up to 80 then it dissapears.. Any Idea? Did i mess up the gap on the plugs? Do i need new wires? I have no clue..

 

did you drop any of the plugs? did you replace the wires? if not, did the metal clip come off of any of them? better yet, just replace them. try gapping them at .050 instead or whatever they were out of the box. also, it's always good to check the gap on a plug, but, from my experience, NGK's come out of the box at what they should be gapped at for MOST applications. so, if you changed the gap dramatically from what it was originally, yes, you screwed up the gap. if it was only a very small amount, no, you didn't.

 

Make sure all your plug wires are all the way on. Check your plugs to make sure you didn't break an insulator when you put them in. If the porcelain is cracked it's a dead player. Close the gap to .035 or .040 and I bet you'll like it.

 

Does mostly everyone run there gap at about 45 on these plus or minus

 

we leave them alone and i believe that they are gapped at around 50. remove them and look for a crack in the porclan.

 

Well.. guess im going to go buy another set of spark plugs and try it again..

 

Definetely check for a crack in the porcelein and look at the tips too. I was just having problems and my no 7 cyclinder had a crack in plug and my no 8 had the tip completely burnt off....my plugs were only a month old too. So i say check for that and make sure all your wires are connected good.

 

So we 5.3 truck guys get some better performance with gaping them at less than .60?

 

The shorter gap will advance your timing to an extent If my truck needed new plugs however, I'd just put delco-remy's back in. I wouldn't fuss with anything else. Your truck is designed to run optimally with the delco plug and I doubt NGK or Bosch has engineered a specific plug just for our motors alone. I had a 91 S10 that I put Bosch platinums in and the damn thing never idled right or was as reponsive as it was with the factory plugs. Same heat range and everything. That there was enough to show me that going with a factory plug is worth saving the headaches of a missing motor or any other ignition problems that may develop with a tune up.

My 2 pennies

 

i've been having a problem with cylinder 7 too.