Pop/back fire
Cruiser
Joined: Jan 2006
Posts: 108
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From:
RE: Pop/back fire
FL_799, I agree with what your saying.
chopperchuck, if the injectors can completely change the values of the pulse going into the engine by volume, what's the O2 sensor going to do? Maybe readjust the air/fuel when it sees a overly rich condition compared to what it's programmed to do.
What you really need to do is change the program for the injector pulse widths and O2 sensors for what you want it to do because the whole purpose of the O2 is to adjust the fuel according to the air entering the engine.
If you install bigger injectors the O2 may compensate that, however the spray pattern may be better at atomization and a more complete fuel burn may be accomplished, all without necessarily running richer.
chopperchuck, if the injectors can completely change the values of the pulse going into the engine by volume, what's the O2 sensor going to do? Maybe readjust the air/fuel when it sees a overly rich condition compared to what it's programmed to do.
What you really need to do is change the program for the injector pulse widths and O2 sensors for what you want it to do because the whole purpose of the O2 is to adjust the fuel according to the air entering the engine.
If you install bigger injectors the O2 may compensate that, however the spray pattern may be better at atomization and a more complete fuel burn may be accomplished, all without necessarily running richer.
Road Master
Joined: Sep 2005
Posts: 858
Likes: 1
From: Upstate NY / San Clemente CA
RE: Pop/back fire
The injector swap was never meant to richen the mix. It was to address the surging at low speegd and cold start issues. The different spray pattern gives a more cindusive burn, and "cures" that problem. A problem that probably would not have occured had the bikesnot been set so lean. Getting a SERT or other ECMcontroller fixes thoseproblems as well, as it richens the mix.
As gar as the occasional pop.......Its aHarley. They are gonna pop a bit from time to time. RIDE THE DAMN THING!
As gar as the occasional pop.......Its aHarley. They are gonna pop a bit from time to time. RIDE THE DAMN THING!
Cruiser
Joined: Feb 2006
Posts: 123
Likes: 0
From:
RE: Pop/back fire
hey FL_799. the dynas are the only bikes that have the O2 sensors or "closed loop" systems. the rest of the harley family runs open loop. i don't know why the standard sizing on the injectors is 3.91 but you can change that in the tuning constants table to the proper size injector that you have and the sert will adjust accordingly.
Road Master
Joined: Dec 2005
Posts: 1,224
Likes: 2
From:
RE: Pop/back fire
You know Chuck, 06 Dyna owners are ahead of the curve on these closed loop systems. The learning curve was quite steep (and there are still more questions then answers), but I think we (as a group) have a good handle on it before everybody else gets it in 07.
Road Master
Joined: Nov 2005
Posts: 1,055
Likes: 0
From: The birthplace of our nation- Philadelphia proud!
RE: Pop/back fire
I thought the 25's that they are using in the 06's are not the same 25's of previous years. I read something that stated the flow rate of the 8's and "new" 25's are the same. It's the spray pattern that is different. As fl_799 stated earlier, I heard that the 25's are a more conical shape spray thus allowing the fuel to atomize more efficiently thus "curing" the cold starts and 1st/2nd gear surges. I have not seen dyno results of the identical bike with 8's than 25's yet. That would be interesting to see. A side-by-side comparison of the two different injectors on the same bike. Then add a SERT, and run the same test. [sm=confused06.gif]
Road Captain
Joined: Sep 2005
Posts: 715
Likes: 0
From: Yaphank, Long Island
RE: Pop/back fire
Well you guys seem to know a little about FI so I have a question, I never really dealt with FI except for the throttle body in my trucks but I never needed to mess with them. I have a stage 1 download V&H longshots a upgraded filter and just installed the V&H fuel pack and put the correct code in that V&H recomends for my set up. I know I should have went with the sert but I dont plan any crazy upgrades for the ride, It seems to run worse now than it did before I installed the fuel pack it hickups sometimes on acceleration and it pops alot on decell is there anything else I can do?
thanks for your time steve
thanks for your time steve
Road Master
Joined: Nov 2005
Posts: 1,055
Likes: 0
From: The birthplace of our nation- Philadelphia proud!
RE: Pop/back fire
Intruder, call V&H support. I heard they have good customer service and support. Maybe they can get you to the correct setting. I have zero experience with the fuel pack but I've heard some good things about them. Call V&H and talk to them. Good Luck.
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Outstanding HDF Member
Joined: Feb 2006
Posts: 2,958
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From: West Tennessee
RE: Pop/back fire
ORIGINAL: Original Junior
That would be interesting to see. A side-by-side comparison of the two different injectors on the same bike. Then add a SERT, and run the same test. [sm=confused06.gif]
That would be interesting to see. A side-by-side comparison of the two different injectors on the same bike. Then add a SERT, and run the same test. [sm=confused06.gif]
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