Experience with P300 and P303

[El_tucanaso]

Just installed a CARB vortech on my ‘20 GT. I have about 200 miles on the setup. This morning, the engine light started blinking and stayed on. Luckily I had the supplied Livernois tuner with me and I was able to see what codes were thrown. Scanner showed p300 (cylinder misfire)and p 303 (cylinder 3 misfire). Car still runs/ran great. When I get off work I’m going to do a crank relearn (never did it after install), check out the spark plug on that cylinder, and start diagnosing. Any one have any experience in this and can chime in? For reference, I’m running the canned tune from livernois (has ran good so far), I’m using NGK 6510 plugs gapped at .28, and because I’m in cali using 91 octane, I’ve been adding 8oz of boostane. Any input is appreciated.

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[cbrtrx]

Use the ford racing m50a plugs and carefully gap them to .028.

 

[Timbuck]

your on the right track. Check the plug , swap coil pack etc to see it you can move po303 code to another cylinder. That will isolate the problem being electrical. Next on list compression text.
my p0303 code didn’t end well... built motor in the works.

boost And 91 is walking a fine line between smiles and tears.

 

[El_tucanaso]

your on the right track. Check the plug , swap coil pack etc to see it you can move po303 code to another cylinder. That will isolate the problem being electrical. Next on list compression text.
my p0303 code didn’t end well... built motor in the works.

boost And 91 is walking a fine line between smiles and tears.

Thanks man. I’m hoping it’s not a ringland failure. That would suck big time. Haha

 

[Garfy]

Thanks man. I’m hoping it’s not a ringland failure. That would suck big time. Haha

I don't know if the "coil swap" idea works because isn't #3 the one with the single spark plug wire going to the plug due to the DI pump off the camshaft?

 

[Driller6262]

Since I went boosted and on e85 I’ve been getting a lot of the p316 which is misfire within the first 1,000 revs … taking it in to see if that’s just a tube and e85 thing …. Runs great other than the light popping on every once in a while

 

[cbrtrx]

Since I went boosted and on e85 I’ve been getting a lot of the p316 which is misfire within the first 1,000 revs … taking it in to see if that’s just a tube and e85 thing …. Runs great other than the light popping on every once in a while

That can happen with e85 sometimes, the tuner will most likely turn off that code.

 

[HKusp]

Thanks man. I’m hoping it’s not a ringland failure. That would suck big time. Haha

If it's a ringland failure, you'd have way wore symptoms. It would run rough, and have a vibration to it, most likely.

 

[El_tucanaso]

If it's a ringland failure, you'd have way wore symptoms. It would run rough, and have a vibration to it, most likely.

appreciate all the replies! Unfortunately, I haven’t had a chance to look at the car since then. My gf forbid me from playing with my toys this weekend and demanded attention. I will definitely keep this post updated though.

 

[HKusp]

appreciate all the replies! Unfortunately, I haven’t had a chance to look at the car since then. My gf forbid me from playing with my toys this weekend and demanded attention. I will definitely keep this post updated though.

Pull a plug and look at it. If you have a boroscope, run it down in there and look around. Harbor Freight has a decent one for not much money. They sell some cheap ones on Amazon that hook to your phone. If you broke a ring land, the plug will look like the following pics and the top of the piston will be missing some chunks.

 

[El_tucanaso]

Pull a plug and look at it. If you have a boroscope, run it down in there and look around. Harbor Freight has a decent one for not much money. They sell some cheap ones on Amazon that hook to your phone. If you broke a ring land, the plug will look like the following pics and the top of the piston will be missing some chunks.

Thank you for the info! I appreciate it greatly. I will definitely purchase a horoscope today. I’m hoping I got time this week to check it out. If not, definitely this Saturday.

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