can someone with tuning background please help me solve a slight problem
04-28-2010, 11:43 PM
#1
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Location: davis
Posts: 497
Car Info: 93 extra slow L
can someone with tuning background please help me solve a slight problem
well what is going on is i get random intake backfire during rev matching down shifts or feathering the throttle in a slide i never had this problem before my af's are good when i loged 3rd and 4th gear pulls i have no knock either from my understanding is that intake backfire is due to lean conditions correct but what is strange is the wide band never see a lean condition when it does happen.
idle afrs float around 14.1 to 14.7
under load at full boost 11.5 to 12.1
im on e85 fyi with dual walbro 255hp pumps
ive replaced fuel filters + pump socks
ive checked fuel pressure and it is good
ive checked for vacuum leaks ect....
noted that im a full time mechanic that is well under paid lol
so any assitance will be a great help but i will understand if your tuning knowlege can not be shared i completely understand but please pm me with any info i will keep all tips between me and whom ever
thank you very much for taking the time to read my bs but please help
Duberx (David)
04-29-2010, 06:10 AM
#3
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Location: Participating in some Anarchy!
Posts: 15,494
Car Info: 2005 LGT wagon
What recirc valve are you using?
What software are you using to tune?
Look at injector overrun?
Are you sure its a front fire and not a back fire?
What software are you using to tune?
Look at injector overrun?
Are you sure its a front fire and not a back fire?
04-29-2010, 07:28 PM
#4
What's your actual mod list? Do you have a BOV or FMIC? Maybe you developed a leak? Can you pinpoint exactly when this started happening? Did you make any changes to your setup or your tune around this time? Did the weather change significantly around this time? Sometimes figuring out when it started happening can give you a clue about the cause.
Thanks
-- Ed
Thanks
-- Ed
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