So i had a random misfire CEL flash at me and then go away. I pulled the plugs and they looked fine. Could they still be bad even though they don't have any black around the arc area (not sure what that is called)?

If this helps, during heavy throttle around 3500-4000 RPM is sputters out and doesn't wanna pull anymore.

 

Do you have stock plugs? And what are they gapped at?

 

They are AC Delco and I'm pretty sure I gapped them for factory specs.

 

Well if it doesn't want to pull anymore and it sputters like a misfire, I'd say you need new plugs. Just a visual inspection literally tells you nothing about if the plug is still good, unless there is a serious issue. Plugs are cheap replace them at least every 50k un-tuned, and every 10-15k tuned to prevent issues.

 

Ok. Yeah I'll do that this week. I put some HEET in my tank to see if it was water in my fuel. Hasn't worked yet.

 

Water in your fuel would cause issues all the time not just WOT. Have any cold start stubling? That's usually a quick indicator of plugs going (cold as in around or below freezing)

 

No. I live in Central Texas. Not a major worry here. The most I get from a cold engine start (as in sitting overnight) is a slightly high idle like 1500-2000 rpms and then it calms down and idles nice with a little pulse here and there

 

That's normal. Just plugs that are going out will cause prolonged cranking and an odd idle intially when its cold.

 

So I should just change the plugs eventhough they "look" good and see what happens?

 

Your ECU recorded more than 200misfires, I think it knows better how the spark plug is. I had the same misfire flashing light, replaced with AC Delco stock plugs, flashing CEL gone, and the replaced plugs visually looked ok.

 

Did you have the sputter as well?

 

Yes. New AC Delco plugs are ~$45 and stick with AC Delco the LNF is picky

Have the parts store pull the codes, if its random misfire and misfire >200 then just replace the plugs.

 

They did the freeze frame on it and it showed up as a P0300 Random Misfire and then I had P0304 #4 Cyl Misfire. That was from snapping the POC trying to put it back in. I'll see if I have the P0304 after I do the plugs.

 

They're $20 on Amazon.

 

had the same issues you did when i bought my LNF, changed plugs gapped to .032 and never had issues

 

What octane you running? If you're skimping on 87 then that would cause a miss. I tried it to see how it would take regular fuel and I consistently had a misfire on one cylinder. 93 all the time is the best.

 

Make sure none of your sparkplug wire/ boots are damaged the boots have a tendency to crack

Ecaulk tell me more about how you cant tell anything from looking at a plug I understand if a plug looks good that doesn't meen it is but you can tell a lot about how the engine is running from just looking at the general condition of the plug

 

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