Fox Spark plugs

Fouling is usually due to too much fuel or insufficient temps.

What were your AFRs on the cruise and at idle? How rich does it swing on tip-in? It was likely too rich.

How did the shop tune your car? Are we talking just fuel pressure & base timing adjustment, or some kind of a chip? What thermostat are you running, and is the ECT coming up enough for the EEC to get to both closed loop and standard fuel tables?

3923s are the right temp range for your setup, but keep in mind that the temp range is designed to reduce detonation at WOT. Colder plugs don't stay as clean, and at street driving loads, they are more likely to foul.

The very tight plug gap doesn't help. It diminishes the spark and the temps. It could be that your ignition system is not up to handle a bigger gap, but more than likely, your tuner reduces the gap because they get fewer complaints that way.

Open the plugs up to .030-.035" and see if that causes any stumble at high RPM under load. If not, that should help with a stronger spark & more heat, which will ensure a more complete burn and hopefully reduce fouling.

Hmm... No idea why it would idle higher after a plug change. That would be a sign of a vacuum leak or IAC incorrectly tuned. What's your TPS set to?

Right on. Good luck, man.

Mattjhop23 said:

Quick build
Stock bottom end 302
trickflow box r intake
harland sharp rockers
V2 on 13lbs of boost
Edelbrock rpm heads
Stock fuel
42lb injectors
Car made 520 wheel, I got it with lower intake leak fixed it. Through brand new autolite 3923 plugs in gapped to .023. Went got tuned and dyno’d very reputable performance shop here in Michigan. Been about 2 months and around 500 miles car wouldn’t start after a 200 mile cruise. Finally fired up drove home compression check, new spark plugs, spark check all good fires up perfect runs great now. Any ideas why plugs were toast already. AFR good,fuel pressure still good.
Recommendations on different plug maybe different heat range? Or more gap?
Old plugs were still gapped .022-.023 some did smell flooded or gassy

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Curious how you like the V2? I’m looking at a full kit locally, guy is in or was in building phase, installed to idle motor other wise no use. Sat on shelf for 4 years and decided to go turbo. Looks clean, sent serial to Vortech and all is good no service etc done it. This is a V2 TI foxbody kit that I could get for 3800. Just not sure if this is to much blower for my set up which is a 302 with heads cam etc. possibly swap to a 351 I have that I want to go 408. Seems like a good deal but not seeing a lot on the V2 setups