What causes backfire - Too lean or too fat?
I've had real rich problems using 46lb injectors especially at idle, so had to go down to 36 lb/hr's. This forced me to completely recalibrate my base fuel map - using DFI 6.32 Gen.
While running down a flat street at medium load in 2nd or 3rd at 3000 RPM and I peg the gas to WOT or close to WOT and my car blows a backfire as loud as a 9" cannon.
Timing seems okay - fuel at that BAR & RPM seem close to 14.7/1.
Any ideas before I blow my whole car up???
While running down a flat street at medium load in 2nd or 3rd at 3000 RPM and I peg the gas to WOT or close to WOT and my car blows a backfire as loud as a 9" cannon.
Timing seems okay - fuel at that BAR & RPM seem close to 14.7/1.Any ideas before I blow my whole car up???
i know on my atv, a lean condition will cause the bike to backfire. a rich condition will usually make the car pretty doggy. do you have stock tuning? if so, you will still probally be rich with the 36 injectors in. sorry, i'm probally not much help
Many people get confused on what a backfire truly is. A backfire is (for lack of a better term) a pop thru the intake tract. It is reffered to a backfire because it backs up the natural flow of air into the engine. This can be caused by several things but the most common would be a lean fuel condition. Now when you hear a pop thru the exhaust system the proper terminology is an afterfire which can be caused by a rich fuel condition. So let us know which you are getting and I bet someone will have some helpful ideas. Hope that helps.
Thanks cef97ws6...
My problem is, as you defined it, an afterfire. At 3000 rpm I stab the throttle and BOOOM! It can be heard for blocks! I do not have stock tuning - I'm using DFI and have calibrated the block-learns for every cell within 3-5% of stoick (spelling) or 14.7/1 air fuel - the closed loop o2 correction handles the rest.
So maybe I am real rich at the point where the BAR jumps down. I'll check that out.
Thanks
Any other ideas?
My problem is, as you defined it, an afterfire. At 3000 rpm I stab the throttle and BOOOM! It can be heard for blocks! I do not have stock tuning - I'm using DFI and have calibrated the block-learns for every cell within 3-5% of stoick (spelling) or 14.7/1 air fuel - the closed loop o2 correction handles the rest.
So maybe I am real rich at the point where the BAR jumps down. I'll check that out.
Thanks
Any other ideas?
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tommalcolm
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Sep 11, 2015 03:39 PM



