SERT and O2 Sensor Problems
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Joined: Dec 2005
Posts: 57
Likes: 0
From: Apple Valley, MN
RE: SERT and O2 Sensor Problems
WideGlide,
I’m curious; did fl_799’s tinkering with your map take care of your problems? Are you still tweaking your map or what’s going on?
How about some follow-up…
There are a lot of us out here in the same boat and we are watching and learning from these posts.
fl_799, keep up the good work and , your posts are an invaluable resource to me . Thanks…
I’m curious; did fl_799’s tinkering with your map take care of your problems? Are you still tweaking your map or what’s going on?
How about some follow-up…
There are a lot of us out here in the same boat and we are watching and learning from these posts.
fl_799, keep up the good work and , your posts are an invaluable resource to me . Thanks…
Road Master
Joined: Dec 2005
Posts: 1,224
Likes: 2
From:
RE: SERT and O2 Sensor Problems
We were taking it a step at a time. The first conservative update I made to the map still had the surge problem. I sent a second update and not heard back yet.
The problem with that map was that the ve values on his modded map that were a few points lower then the unmodified map i.e. serveral percent leaner. With the aftermarket exhaust, these values should be a few increments HIGHER then the factory map so he is certainly running lean especially in the 20 map range where these problems are. I bet his lean surge is off the charts and you can see this just by looking at the map itself!
Personally, I know we can eliminate his surging at 2000 RPM's but how good is the rest of that map? How did those tuners come up with the VE table values? I haven't got a clue and I'm no expert by any means, just a tinkerer whose become slightly educated on how these things work to get my bike running well.
Finding the VE values is the key to the entire tune on all these bikes either closed loop or open loop. The method for determining the Volumetric efficiency is simple. You set every single cell in the air fuel ratio table to 13.3 and stick a wide band O2 sensor on each cylinder. You adjust the VE table values until the wide band o2 reading from the actual exhaust matches the 13.3:1 we entered in the A/F table. This is right out of the instruction book and the foundation for tuning any fuel injection system map. Any dyno shop worth their salt can accomplish this whether they 'know' the SERT or not. They do not have to be experts at the SERT, just follow some simple instructions.
The problem with that map was that the ve values on his modded map that were a few points lower then the unmodified map i.e. serveral percent leaner. With the aftermarket exhaust, these values should be a few increments HIGHER then the factory map so he is certainly running lean especially in the 20 map range where these problems are. I bet his lean surge is off the charts and you can see this just by looking at the map itself!
Personally, I know we can eliminate his surging at 2000 RPM's but how good is the rest of that map? How did those tuners come up with the VE table values? I haven't got a clue and I'm no expert by any means, just a tinkerer whose become slightly educated on how these things work to get my bike running well.
Finding the VE values is the key to the entire tune on all these bikes either closed loop or open loop. The method for determining the Volumetric efficiency is simple. You set every single cell in the air fuel ratio table to 13.3 and stick a wide band O2 sensor on each cylinder. You adjust the VE table values until the wide band o2 reading from the actual exhaust matches the 13.3:1 we entered in the A/F table. This is right out of the instruction book and the foundation for tuning any fuel injection system map. Any dyno shop worth their salt can accomplish this whether they 'know' the SERT or not. They do not have to be experts at the SERT, just follow some simple instructions.
Road Captain
Joined: Dec 2005
Posts: 536
Likes: 0
From: AUSTRALIA
RE: SERT and O2 Sensor Problems
The VE tables is the area I also looked at. I felt a slight flutter but wouldn't call it surging so I changed the VE values of the front to match the rear. I believe that if both cylinders are receiving equil air as with carb version there should be a balanced combustion as one piston decending at the same speed as the other. This has fixed the problem in my case and the bike feels to be smoother overall.
Road Master
Joined: Dec 2005
Posts: 1,224
Likes: 2
From:
RE: SERT and O2 Sensor Problems
The Daytona WEGO II with data logging is an excellent option. Taking it one step further: combine the Daytona Twin Scan tool with WEGO II twin o2 sensor unit and it will make a printout with suggestions to the VE tables (w/ Sert) as as shown below.
This is showing exact settings to make to the VE tables using the WEGO and Twin Scan.
In any case, once you add up the SERT, the WEGO, Twin Scan 88 and other misc parts, you are running into some serious money no question about it. But the wego systems is tangable and with the exception of the sert, mostly reusable on other vehicles. Makes the Terry Components Terminal Velocity closed loop FI system look that much more attractive once you consider the cost of all these devices add up to a far greater cost.
This is showing exact settings to make to the VE tables using the WEGO and Twin Scan.
In any case, once you add up the SERT, the WEGO, Twin Scan 88 and other misc parts, you are running into some serious money no question about it. But the wego systems is tangable and with the exception of the sert, mostly reusable on other vehicles. Makes the Terry Components Terminal Velocity closed loop FI system look that much more attractive once you consider the cost of all these devices add up to a far greater cost.
Advanced
Joined: Nov 2005
Posts: 91
Likes: 0
From: Southern, Md
RE: SERT and O2 Sensor Problems
hey wideglide, my 06 street bob had that problem stock right off the show room floor, they had it for 22 days and i was pissed. they ended up changing the whole intake assembly. after a new ecm, injectors, 2 sensor which i cant recall right now but i will think about it. now i have se a/cleaner, se lls slash downs no baffles and power commander usb with map m811-004. its sweet. no popping, coughing just alot of get up and go.
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TNBagger
Ignition/Tuner/ECM/Fuel Injection
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Nov 8, 2007 07:59 AM
