I have a spark plug that has hairline cracks on it. I was just wondering if it would make my car backfire and hesitate. My RPM's are also jumping but I think that has to do with my intake that keeps falling off around the MAF. If it wouldn't make my car run terrible would could. O yeah and at night i looked under the hood and saw blue light coming from the plugs.

 

o and since i didnt put a signature in i have a 94 camaro z28 with longtube headers, borla exhaust and K&N cold air intake. 74k miles plugs and wires less than a year old. Water pump is fairly new along with the cap and rotor (no I didn't replace it previous owner did). And the car does this all the time well it hesitates all of the time but it won't always backfire.

 

If the porcelain is cracked, that plug is going to have a hard time firing. Definitely have it replaced.

 

A plug with a crack would definitely do that. You're dealing with >20KV and it will do anything to go to ground - thus a cracked plug will surely cause a misfire and all the related problems. Sometimes people have a hard time installing certain plugs and either crack one with the wrench or by dropping it. And getting any tiny crack in the porcelain will cause the plug to be faulty.

 

are you sure its a crack and not carbon tracking, they can look similar and would explain the blue light you see. the spark is arcing (leaking) out from the spark plug boot. a bad spark plug can cause this and a bad boot can cause this, i would recommend you replace both in sets

also, get that intake track fixed so we can start ruling out problems one at a time

i always thought it was closer to 30-40

 

Yeah i took the plug out and felt it. It is for sure cracked in two different places. And the intake at one point was secured tightly, but still had the same problems. I should be getting the new plugs in tomorrow or wednesday and I will let you know then!

 

Good thing you are replacing them all around though, arcing plugs are definitely going to affect your car. Since you are doing plugs, you might want to consider plug wires as well.

 

why dont you go ahead and make a sig now so that in the future it will be easier for people to help you

since they are less than a year old as previously stated i would think they "should" be ok

 

When i got the car it needed new plugs and wires but the plugs and wires were both 6 months old. One of the wires burnt and a plug cracked really bad on it. So I'm not surprised that another one cracked but all of the wires look fine.

 

Found out my coil wire was arcing so I'm going to replace that today

 

replaced my coil wire and still runs like crap. Saw arcing around the coil and replaced that and still runs like crap haha. I have noticed though that it runs the worst from a cold start. As the car warms up it runs a lot better. I'mm thinking a possible bad connection on the coil wire to the distributor? If the connection was dirty would it cause it to arch?

 

If you are seeing arcing around the coil, that's a good sign you need new plugs and wires.

 

I replaced them about a year ago. I can check the plugs and wires again just to make sure. All help is much appreciated!

 

now that i think about it when i first had backfiring and missing it would backfire when i first started it up maybe i burnt a different wire and thats why its acting a little bit different

 

ok I had it scanned for code after finally finding a shop that could. Came up MAF problems. So I cleaned it and it didn't fix it. I bought a new one and it didn't fix it. so i went back to the shop he scanned it again MAF still came up he cleared it looked at all of the data and found that my intake manifold pressure is 10 at idle and he said it should be 18. Could this mean a vacuum leak? He sprayed carb cleaner around the intake manifold and couldn't find any leaks. Any ideas?