I pulled 6 of the 8 plugs on my Z28 and I noticted that the gap was considerably larger on the old spark plugs compared to the new ones. I'm not sure how long the old AC Delco R43TS's had been in the car. The car has a stock ignition and has been running on codes 32, and the VSS code for a few months now. I'm going to run out and get a spark plug gap tool and see just how large the gap is. What are these plugs telling me? Thanks in advance

 

They dont look too bad, maybe some slight leaking from the valveseals as they do look a little goopy around the outside.

 

Yeah, my car does tend to puff some smoke. It has nearly 170k on the clock and runs fairly strong still. I was thinking for a while that I needed new rings due to the fact that I got the grey smoke plumes out of the tailpipes at every take off. Any clue why the post and electrodes are that whiteish color?

 

I believe it looks a little lean, you want it to look a wheat golden brown.

 

Could that be why it is down on power?

 

A slightly lean mixture will make more power but a detonation condition, if it iverly lean the computer will put the timing back due to detonation, with timing back it will feel sluggish.

 

they look pretty old, easiest way(imo) to do it is just replace them all

run it for a few days maybe and then check out number 1 and see if the "golden brown" Condition is there( good!lol)

 

Replace your plugs with CR45ts they are a little hotter than the 43s i have had a set in my 92 L03 for over 3 years now and no probs. Oh forgot to mention gap at .035

 

just one question whats with all the shiney specks of stiff on them?

 

Pretty sure that's evidence of some detonation, which would support the 'going lean' theory.

 

The shiny specks are metal shavings from the porting job on the plenum. I left a few of the plugs on the table when I was porting. Funny thing is, they can't be easily seen with the naked eye. Would upping my fuel pressure help my lean condition?

 

well yes uping the pressure will help the lean condition but might make it fat in other areas depends on where it is lean throw a new set of plugs in take it for a spin as is hammer down for about 1 minute then park it take a couple out and re read them they should have a slight tannish color on one side