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Changing Spark Plugs

FiestaSTdude

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#1
I'm changing the spark plugs and ignition coils on my FiST and I have a few questions:
When y'all change the plugs and coils, is there anything else that you do as standard maintenance (specifically related to the spark plugs)?
I was looking at NGK plugs (rock auto part number 94769). What's a good plug to use for a stock or cobb stage 1 tune? I'm more concerned about reliability over performance.
What is the torque specs and spark plug gaps for the FiST?
 


TyphoonFiST

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#2
I'm changing the spark plugs and ignition coils on my FiST and I have a few questions:
When y'all change the plugs and coils, is there anything else that you do as standard maintenance (specifically related to the spark plugs)?
I was looking at NGK plugs (rock auto part number 94769). What's a good plug to use for a stock or cobb stage 1 tune? I'm more concerned about reliability over performance.
What is the torque specs and spark plug gaps for the FiST?
Stock FiST? Mileage?

Sent from my SM-N975U1 using Tapatalk
 


SrsBsns

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#3
Coils should last for a while and unless you have a problem with them, I wouldn't worry about them.
While you're doing the plugs, I would recommend just doing a visual inspection of the system, looking at the wires to make sure they're in good shape.
If you're going iridium, you want the NGK 6509 (or 6510- one-step colder) plugs with a gap of .025.
I would think no more than 10-12lbs to torque them.

There's a "debate" about running colder plugs. The consensus seems to be that you need to be making a decent amount of hp over stock to need them but a lot of people use them with OTS tunes, myself included.
 


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#5
Coils should last for a while and unless you have a problem with them, I wouldn't worry about them.
While you're doing the plugs, I would recommend just doing a visual inspection of the system, looking at the wires to make sure they're in good shape.
If you're going iridium, you want the NGK 6509 (or 6510- one-step colder) plugs with a gap of .025.
I would think no more than 10-12lbs to torque them.

There's a "debate" about running colder plugs. The consensus seems to be that you need to be making a decent amount of hp over stock to need them but a lot of people use them with OTS tunes, myself included.
Torque to 10lbs....unscrew a half-turn or so and re-torque to 11lbs. This pre-crushes the ring and seats it solid. I disagree on anti-sieze... I use Copaslip (there is no better IMO). One drop on two sides, just above the first thread so it spreads as you screw the plug in. Don't get the anti-sieze on the pos electrode or ground electrode. If you do, clean well with spray Brakekleen and start again. Anytime you screw steel into aluminum you should use anti-sieze.
 


OP
FiestaSTdude

FiestaSTdude

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Thread Starter #6
Stock FiST? Mileage?
87k miles, stock engine. I have a Cobb accessport on the way, so I might go to whatever the tamest cobb tune is.

Thanks everyone for the info. Why would colder plugs be better than stock?
 


green_henry

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#7
87k miles, stock engine. I have a Cobb accessport on the way, so I might go to whatever the tamest cobb tune is.

Thanks everyone for the info. Why would colder plugs be better than stock?
Colder plugs should be less likely to knock. I installed them with my Dizzy tune and they work fine; I think cold starts in freezing conditions might be hesitant, but no issues in more temperate climes ;)
 


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OP
FiestaSTdude

FiestaSTdude

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Thread Starter #12

Lays

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#15
COLDER PLUGS HAVE ISSUES STARTING ONCE WARM

PEOPLE LOOK AT YOU REAL FUNNY AFTER YOU GET GAS, ASK ME HOW I KNOW
Must be something else, my step colder plugs gapped at .026 start right up after getting gas. Perhaps check your purge valve if it's after fillups.
 


OP
FiestaSTdude

FiestaSTdude

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Thread Starter #16
Must be something else, my step colder plugs gapped at .026 start right up after getting gas. Perhaps check your purge valve if it's after fillups.
My purge valve went bad at around 60k. My FiST took FOREVER to start after filling up, it was very annoying.
 


OP
FiestaSTdude

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Thread Starter #18
Mine always shudders after filling up. It's a known issue with these cars. My car threw a code when the purge valve went.
 


HardBoiledEgg

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#20
ITS THE PLUGS. I'VE WENT BACK TO STOCK MULTIPULE TIMES FOR THIS EXSACT REASON. ANYTIME AFTER DRIVING AND IT ABOUT 5-10 MINUTES OF BEING PARKED IT DOES CRANK LONG. CHANGED THE PLUGS TO FACTORY AND NO PROBLEM. BUT AS OF NOW IM TUNED WITH DIZZY SO I HAVE TO RUN THE PLUGS
 




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