So a guy from the forum asked me to hook up hptuners to see what was going on with his car. Said he thought it was running rich. Commanded AFR at Wot was 11.3. Anyways he went home and changed spark plugs and then the issue started to happen. Believe he is currently gapped at .040, should it not be around .035. He is a ZZP Stage 3. Car is throwing P0300 code for missfire.

I see a weird missfire on cyl 2 & 3. Its constantly cycles to 99 and then repeats itself over and over again. We swapped coil and problem stays there. Also moved injectors to see if it moved but stayed in 2 & 3. Car is commanding 10.1 sitting at idle as well.

Anyone got any ideas?

Here is what it looks like?

http://www.youtube.com/watch?v=pV4YJL5pp1E

Was just looking at his log an his AFR is not moving at all?

 

Can you email me a log+config file?

 

Attached here:

Missfire Repeating - HP Tuners Bulletin Board

 

I would imagine if it started after he changed them, he messed up some how, check the wires to the coils, but most likely it's a plug problem.
What plugs us he running, mods? I imgine if he's modded there are colder heat range, maybe try putting the old ones back in for comparison sake.
I always run the ngk brk7e or the superceeded number 4644

maybe also try switching coils around to different cyl to see if it follows, if yes, it a coil problem,
btw .040 is kinda wide, take them down to .035

 

edit, reading> me haha

 

I'll ook at it as we'll when I get a chance. Did u ook at hos misfire revolutions. Were they changed with his tune. Also wut plugs, and the gap needs to be. Highest at. 032 I feel with a pulley lowere then 2.9 there is a lot of blow out spark (blow by) so gap the plugs correct. Then log it. If idle is 10- and below 14.7 and is commanding this. Tben either in the tune its commanding this, or he is in open loop and its not gettinf to operating temps. Has a exaust leak and or vacuum leak.

 

Sorry bout grammar on the phone at micky ds lol.

 

blow by has nothing to do with spark plus, blow out was the correct term.

.032 is a also a good suggestion, idle won't really care about much less then .035 or not, but to run it from now on. .032 is golden

 

Correct term for u sir.I say blow,by for anything lmao. I know the correct term and wut its meant for. Blow bye blah blah blah. Yeah I'm a tc and I tune so I know the correct term lol. But spark blowout. I know as well. If he can change the dwell of the spark then change it. I change mine in the upper loads in all cars I tune with a sc or tc. I've owned a sc ss and did the same. I got p0300 randomly. Bad gas is usally wut caused mine.

 

when I did my head swap I must have dropped my plug, looked fine, so I put it in, 5 minutes later and driving developed a bad missfire, I pulled the plugs and found a hairline crack in number one plug