CarAteMyMoney

iTrader: (2)

The car is a '98 Z28 w/ 86k miles... it had the original plugs and wires..

the old plugs that came out had a gap of .070

the factory spec is .060 and the plugs that went in are the ngk tr55's.. they all seem to be gapped to around .050-055

after starting it up again, there's a slight miss at idle.. my friends hp tuner says there's misses in 3,4,5 cylinders... not enough to throw a code. but enough to run like doo doo at idle but it clears up at higher rpm's

should i regap the ngk's to 70 or should i put the stock ones back in?

and is there anything else i should be checking?

BLACK2001SS

Check to make shure all the wires are connected good the gap isnt going to cause a missfire.

King Nothing

iTrader: (9)

yeah check to make sure you hear the clicking noise when your puttin the wires on, no click=not on

CarAteMyMoney

iTrader: (2)

yeah, theyre definitely connected right - 1 click on the plug, and 2 clicks on the coil

BLACK2001SS

well kinda pull on them a little see if you find one that just wants to slip off I know the one on the pass side rear is a SOB to get at. But I'm telling you that thier is no reason that that gap you have is going to cause a missfire. But I could be wrong I dont know much about those plugs seems like alot of people have them and recomend them though.

Steve Bryant

iTrader: (1)

Try changing back to your old wires to see if there's some problem with the wires. Check the ohmic reading for the new wires (and check the old ones while you're at it). Label the wires with a piece of masking tape (1 through 8) so you can keep up with what's what. Then you could also switch back to the old plugs in 3, 4 and 5 just to troubleshoot.

Steve

CarAteMyMoney

iTrader: (2)

we used 2 good wires from my friend's z28 and the problem didn't change, the only think i can think of is the plugs

injector balance test didn't come up with anything out of the ordinary

apex1

ngk tr55's are all junk imho. Stick with stock plugs and stock wires. Unless you're making 500whp you wont need to change.

CarAteMyMoney

iTrader: (2)

well that's strange.. miss was in cyl 3,4,5 .... i put the stock plugs back in just those 3 cylinders and she runs like a dream again. i guess it didn't like the NGK's

what possible reason would there be for only 3 cylinders running like crap with ngk's gapped at .055

mtxfrk2k1

hope i dont run into this.. im gettin ready to do plugs and wires next weekend

Michael02hawk

iTrader: (26)

I had one plug wire this year that kept slipping off of the spark plug!

The damn thing clicked on each time just fine, but a slight pull, and the wire fell off into my hands.

Even when I tested this wire on an old plug (outside the car) sure enough, it just didnt catch or latch. I swapped out the wire with a new one (i jave spares), it clicked in and stuck just fine.

Cole Train

iTrader: (30)

i'd guess maybe the plugs have cracks in the porceline. Just a thought there~Cole~

MaroonLS1

iTrader: (5)

When connecting wires to plugs youre gonna hear (1) click. When connecting the other end of wire to the coil pack it will click twice.

CarAteMyMoney

iTrader: (2)

yup 2 clicks.. that wasn't the issue. 3 of the 8 plugs i got from summit seemed to be bad, since swapping in the old plugs in the cylinders with the miss cleared it up

how could a new spark plug be bad? the gaps were fine

ramairracer

iTrader: (13)

maybe you over tighten'd them and they have small hair line cracks,
ive seen some dumbasses tighten them with an air ratchet, thats begging for a miss

King Nothing

iTrader: (9)

ok i just checked my tops and they only click once wtf

99blancoSS

iTrader: (115)

Sounds like your not seating the coil end correctly. Nothing wrong with NGk plugs at all. Your not getting the wires on correctly.