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Hi,

Apologies to you guys if this issue has been asked and resolved on other threads but I did try to search and have not found anything that aligns to my issues.

Right out of the gate, I will mention that I have a Procharger installed running at 6 PSI.

The problem is that I am having a P0300 error code come up when checking codes on the Predator. I ran the diagnostic because recently, the car started misfiring at around 4500 to 5000 rpm, I don't necessarily have to be flooring the accelerator for this to happen, I can gently go up the curve and it will start to buck and hesitate no matter how much load I apply. I have not noticed this happening on 1st and 2nd, I can only replicate this issue on the same rev range when on 3rd and above.

2 things happened recently which may have contributed to the issue, first I had the O2 sensors changed because they were kicking up CELs. This was resolved by my mechanic. After the swap, the car had been running fine for a while but then hesitation issues started to happen. I thought it was a spark plug problem so I got them all changed with NGK LZTR6AIX-13 gapped at 0.030. The problem did not go away. I did notice that 2 of the removed plugs had corrosion at the contact point, (the portion that meets the coilpack sleeve), and that a leaking screenwasher jet was dropping fluid onto one of the coil packs. However, if that was the issue then there would only be a misfire on one of the cylinders and not a random misfire right?

Since then I have been trying to figure out what PIDs I should log to determine what component was acting out of normal parameters so that I could get to the root cause quickly but there is nothing on the net. If you guys can point me to the right metrics to log then I hope that I may be able to figure out the problem without having to pay thousands for my mechanic to blindly go around without reaching any conclusion. Here in Denmark we don't have any real tuners so I cannot really go to anyone for help, I have to figure it out myself and then just tell them to do the work to fix things.

I need to get the car back out onto the Autobahn and resume humiliating elitest douchebags who think they have fast cars.

Please help me!!!! :D

Marcus.
 

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Sounds like it might be spark blowout. I see you've got new plugs gapped at .030 in. You may want to try closing them down a bit more.....025 in. or so. Also, since you'll be reinstalling the same plugs, be sure to do this job when the engine is cold and use a SMALL dab of anti-seize compound.....don't want to ruin the heads.
 

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Discussion Starter #3
Sounds like it might be spark blowout. I see you've got new plugs gapped at .030 in. You may want to try closing them down a bit more.....025 in. or so. Also, since you'll be reinstalling the same plugs, be sure to do this job when the engine is cold and use a SMALL dab of anti-seize compound.....don't want to ruin the heads.
Thanks Magnuman. I just got a response from the guys at ProCharger and they suggested that I have gone too tight on the gap and should aim for 0.035 to 0.040. Does that make sense to you or would I really be heading in the wrong direction if I follow their advice? :oops:
 

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If it is indeed spark blowout (we don't know for sure yet), the normal fix is to reduce the gap a little at a time. You may want to do an internet search on spark blowout and see if you can find further clues that match what is happening. On the other side of this, if the Procharger folks are telling you to widen the gap, it's their blower setup (and they normally know their stuff), so you may want to try what they say first. Six pounds of boost isn't really very much and I wouldn't think you'd be getting blowout with that boost.

Some other things that come to mind are the coils...are they real old and the boots worn, and the spark plug type (iridium) and heat range may still be a little too hot due to the increased heat and cylinder pressure. General rule of thumb on the heat range is one range cooler for each 75-100 hp. increase. Also, some folks with forced induction swear by copper core plugs, as the platinum/iridium ones act like heat sinks and can cause pre-ignition. Have you "read" the plugs yet to see if they're burning properly....mixture set properly for forced induction.....generally about 11.5-12.0:1 if engine innards are stock? Who did the tune on the engine? What type/octane fuel do you use? How much timing are you running....not more than about 20* BTDC I hope, again depending on whether the rotating assembly is stock and the cam timing. Bottom line is that there are many variables, and even more critical when forced induction is used. Real easy to blow an engine if everything is not set up properly.

Keep us posted on your findings and fixes..
 
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