So my car is cammed and header car and its misfired for the longest time in idle until you turn the ac on it loads up the engine a bit and smooths out and dosent misfire at all. Is this a fueling problem? Does the pcm add more fuel when ac comes on? Is there any way to add fuel to make the misfires go away? Car pulls like crazy and every fueling and ignition component has been replaced and engine is healthy compression and dosent burn a drop of oil.
What kind of car?
Have a tune file?
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
Yea i do have a tune file and its a 1999 buick regal gs with a zzp vs camshaft
Post it up here.
The VS cam shouldn't need the P0300 disabled to stop the random misfire code from popping if you are getting it. It's a much smaller cam than the XP or XPZ that will trip that code.
What spark plug gap are you running and what spark plugs?
Too large of gap and wrong plugs will cause this issue too. I suggest a .045 to .050 gap with cooper plugs on these 3800's when modded. Stock iridium style plugs don't seem to take as well with mods and you can never run platinum plugs in a 3800, the waste spark ignition system eats them alive.
You could also raise the idle rpm too depending on what it's set at.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
I have raised the idle and deleted that code out but you can feel the car stumbling and it still picks them up on the scanner. Also I have always run autolite 104 spark plugs and i think the gap is atound what you said. Not 100% sure though. What plugs would you run?Originally Posted by 5FDP
Really need to see a log. Post up log and tune file, if you can.
Also you can log the car and check for individual misfires, to see it is mainly one or two cylinders. Could be a coil issue, but doubt it if it goes away with extra load on the engine from the a/c compressor.
No way for us to know without seeing data or knowing more. Share with us.
No vacuum leaks or air leaks after MAF?
How are your fuel trims?
Just looked im actually running iridium plugs xp autolite 104s not the regular autolite 104
I will get one tonight and post it up. Do you want just a idle log or wot or crusing or just a mix.
Sure everything in a small 10-15min log should show everything.
Post you tune file here too.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
^This^
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