Misfiring Issue I Searched.
Dec 22, 2010, 05:07 AM
#31
Evolving Member
I just had a similar problem (until yesterday) and after trying plugs, plug gaps, coils, plug leads, timing map, and boost leaks the problem still persisted. In my case it was always around 6300 6500 rpm and was a soft stutter and then kept going.
So to narrow down the causes I switched off NLTS and launch control and in neutral I just stepped on the throttle lightly and went through the whole rpm range up to 7500, and everytime I would get the soft stutter around the mentioned rpm range, so now at least I knew it wasn´t load or boost or timing related! Since I had a newer cam angle sensor laying around I changed that and the problem was totaly cured!!
.
So to narrow down the causes I switched off NLTS and launch control and in neutral I just stepped on the throttle lightly and went through the whole rpm range up to 7500, and everytime I would get the soft stutter around the mentioned rpm range, so now at least I knew it wasn´t load or boost or timing related! Since I had a newer cam angle sensor laying around I changed that and the problem was totaly cured!!
.
Dec 22, 2010, 05:31 AM
#32
Evolving Member
iTrader: (16)
Join Date: Jun 2006
Location: Atlanta
Posts: 205
Likes: 0
Received 0 Likes
on
0 Posts
I had a problem where mine would only break up under boost. First I tried a new sparktech cop bacause I thought it was the coild packs. Then I replaced the cam sensor and still no luck. Next came the MAF sensor and I still had the problem. Finally I replaced the MAP sensor on the manifold and the car was back in business.
Dec 22, 2010, 01:47 PM
#33
Well replaced my plugs again and wires and car was fine for three pulls regapped plugs to. 028 and it felt like it gained 50hp and was fine for two pulls then broke up again.. changed plugs again no issues galled at. 22 after three pulls breaks up...
Dec 23, 2010, 04:02 AM
#34
Evolved Member
Hi Guys,
today ive went for a re-tune and at first everything looks fine as i am happily getting 330whp with only 1.2bar (Low) of boost and this is the wonder from GSC S2 cams but when my tuner set for 1.5bar of boost my car miss fire...My mech advise me to go for an Injectors cleanning and do anyone knows what is the healthy omps reading for a plug cables?
Curently im using ngk spark cables.
My spark plugs when took out from the engine all look whitish on the plug tip.
Hope can settle the problem after cleaning the injectors tmr.
today ive went for a re-tune and at first everything looks fine as i am happily getting 330whp with only 1.2bar (Low) of boost and this is the wonder from GSC S2 cams but when my tuner set for 1.5bar of boost my car miss fire...My mech advise me to go for an Injectors cleanning and do anyone knows what is the healthy omps reading for a plug cables?
Curently im using ngk spark cables.
My spark plugs when took out from the engine all look whitish on the plug tip.
Hope can settle the problem after cleaning the injectors tmr.
Dec 24, 2010, 07:51 PM
#35
My injectors are brand new ID1000CC's Got my wastegate working on my car and it doesnt break up at 15psi its perfect... ANything higher then 20psi brakes up... Fuel CUt is bypassed has new plugs now... new wires... new battery... new coilpacks... Still breaks up. I am completely out of ideas. If I put in new plugs in Its Fine for 3 pulls after that the plugs seem like they die and it breaks up again. Im lost...
Dec 24, 2010, 08:46 PM
#36
Evolved Member
My injectors are brand new ID1000CC's Got my wastegate working on my car and it doesnt break up at 15psi its perfect... ANything higher then 20psi brakes up... Fuel CUt is bypassed has new plugs now... new wires... new battery... new coilpacks... Still breaks up. I am completely out of ideas. If I put in new plugs in Its Fine for 3 pulls after that the plugs seem like they die and it breaks up again. Im lost...
Dec 25, 2010, 09:13 AM
#37
Evolved Member
well when you installed the spark plug wires, did you put any dye eletric grease in the coil boots?? are the coil boots cracked?? are they on right??, if you dont hear pop into place then there not on right. On a personal note i ended up havin a small misfire issue, which come to find out was due to the fact that my spark plug socket the rubber insert where the back of the plug goes in ended up gettin lodged in my #2 cylinder after reinstalling plugs and i didnt realize it...so stupid on my part. but my tuner caught it for me, so somethin stupid and simple is usually the big issues haha
Dec 25, 2010, 06:56 PM
#40
well when you installed the spark plug wires, did you put any dye eletric grease in the coil boots?? are the coil boots cracked?? are they on right??, if you dont hear pop into place then there not on right. On a personal note i ended up havin a small misfire issue, which come to find out was due to the fact that my spark plug socket the rubber insert where the back of the plug goes in ended up gettin lodged in my #2 cylinder after reinstalling plugs and i didnt realize it...so stupid on my part. but my tuner caught it for me, so somethin stupid and simple is usually the big issues haha
Dec 25, 2010, 07:47 PM
#43
Flooded under boost, especially with low timing, will pop bang spit and sputter. Leaning it to 11.5 will be fine, if its still doing it then there are other issues. I havent been able to get a car to run misfire free at 10.5 over 25psi, so assuming low timing and maybe a WB thats a little off and it can easily be the cause.
Dec 26, 2010, 10:12 PM
#44
Flooded under boost, especially with low timing, will pop bang spit and sputter. Leaning it to 11.5 will be fine, if its still doing it then there are other issues. I havent been able to get a car to run misfire free at 10.5 over 25psi, so assuming low timing and maybe a WB thats a little off and it can easily be the cause.
Dec 27, 2010, 04:47 AM
#45
Evolving Member
I think that JohnBradley is saying to bring the AFR to 11.5 and see if that helps, not to increase timing while you still have AFR of 10.xx
Hope this works out for you.
Hope this works out for you.