Gen 3.5 Drop In Cruising Gas Mileage

[Dr. Dolittle]

The gen 3 is a bit different than the previous ones but the the second setting is the accelerator pump function and any setting other than "0" on any of the first 3 settings is adding fuel over and above the base map in the ECM. I don't believe you can remove any fuel regardless of the setting you use.

Just spent some more time on the website (EFI Controllers - Electronic Jet Kit - Motorcycles, ATVs, UTVs, Sportbikes, Snowmobiles, Watercraft, Dirt Bikes) and reviewing the instructions that came with my TFI.

According to their website, the GEN 3.5 TFI is able to subtract fuel from the stock setting. Not quite sure if I understand how this happens with a piggy back TFI like this one.

The included instruction sheet says, "Light settings for GEN 3.5 controllers below 3 are SUBTRACTING fuel from the STOCK fuel level."

Given that this is all true, by following their recommended settings, I'm running barely above stock in Mode 1 (cruise fuel) and stock in Modes 2 and 3 (acceleration fuel and full throttle fuel) and still seeing a large drop in mileage!

My bike is running fine and I didn't notice the drop in mileage until the interstate cruise home from Biketoberfest. But now I'm worried that I'm running just as lean as stock or worse since I've done the Stage I.

Needless to say I'm as confused as ever over this. Sure hope someone from Dobeck can clear this up for me soon.

 

[Hoople]

Doc,
1) You are without question running a Gen 3.5 and not a Gen3
2) Did you by-pass your O2 sensors or have you changed their bias voltage in any way.
3) You do NOT have any Historical Codes logged in your speedo. (Boot,,check engine light comes ON, then OFF, then ON then OFF)
4) You did get better mileage (+10mpg) at 1 time even while using Ethanol fuel.

 

[Dr. Dolittle]

Doc,
1) You are without question running a Gen 3.5 and not a Gen3

I had a long discussion with them about this since my unit actually says GEN 3 on it. He talked me through the different wiring colors/grouping and assured me that I had a GEN 3.5.


2) Did you by-pass your O2 sensors or have you changed their bias voltage in any way.

O2 sensors bypassed as per the instructions.


3) You do NOT have any Historical Codes logged in your speedo. (Boot,,check engine light comes ON, then OFF, then ON then OFF)

No codes - this is the first thing I checked when I got home that night.


4) You did get better mileage (+10mpg) at 1 time even while using Ethanol fuel.

I used to get at least in the mid 40's MPG at steady interstate cruising speeds. Averaged 35 MPG over 3 tanks of fuel on the way home from just south of Ocala.

Thanks for taking the time to help me figure this out!

 

[Hoople]

Doc,
The instruction set you linked me to does not seem to have any information on O2 bypass. Where would I find that. The instruction set was only 2 pages and nothing was covered regarding O2 sensors. It says the kit contains "O2 sensor bypass-Optional" but does not talk about it.

So at this time, your O2 sensors are BOTH disconnected and tucked away.

I do trust the people you spoke with but I remain uncomfortable about you having a Gen3.5 vs Gen3. I would have to compare/view the Output pulse width to the Input pulse width with my own eyes and see if the output could be made shorter than the input.

 

[Dr. Dolittle]

Doc,
The instruction set you linked me to does not seem to have any information on O2 bypass. Where would I find that. The instruction set was only 2 pages and nothing was covered regarding O2 sensors. It says the kit contains "O2 sensor bypass-Optional" but does not talk about it.

So at this time, your O2 sensors are BOTH disconnected and tucked away.

I do trust the people you spoke with but I remain uncomfortable about you having a Gen3.5 vs Gen3. I would have to compare/view the Output pulse width to the Input pulse width with my own eyes and see if the output could be made shorter than the input.

My instructions also say, "Oxygen Sensor Bypasses - Optional." But then in very small print beneath this it says, "for models with OEM Oxygen Sensors." Since my bike had OEM O2 Sensors, I bypassed them.

I was also hard to convince on the 3 vs 3.5 issue. Chris said they had a small run of 3.5 controllers that were mislabeled as GEN 3. However, he talked me through the way the wires are grouped by color going into the controller and my wire configuration matched the GEN 3.5 description.

 

[Hoople]

Since my bike had OEM O2 Sensors, I bypassed them.

And how did you bypass them. What was used? A "deadheaded" plug?

What I would really like to know is how on earth you can have both your O2 sensors bypassed and your Not logging a pair of Historical codes in the ECM. When O2 sensors are bypassed, their outputs are tied (or fixed) to 1 single value. The ECM really should see the O2 sensors are always staying at a fixed value and then throw a pair of P0131-P0151 codes (or some other O2 sensor code). I can not believe the Delphi firmware is not advanced enough to see a sleeping O2 sensor. That part has me wondering.

 

[Dead Horse Racing]

perhaps theres a problem with the tuner? they pretty much have a unlimited 2 year warranty. have them warranty it and see if its any extra money to have one which utilizes the O2 sensors.

the bypass kit should consist of a plug with diodes in it to fool the ecm to thinking the O2's are operating properly.i haven't seen one with my own 2 eyes but thats the way i understood it from dobecks

 

[Dr. Dolittle]

And how did you bypass them. What was used? A "deadheaded" plug?

the bypass kit should consist of a plug with diodes in it to fool the ecm to thinking the O2's are operating properly.i haven't seen one with my own 2 eyes but thats the way i understood it from dobecks

I don't know what you would call the plug - it was the one included with the TFI. Perhaps DHR describes it in his post better than I could.

I'm starting to wonder if one of my winter projects should be to totally uninstall everything I did with this kit and send it back to Dobeck for evaluation. Changing the settings on this thing all the way up to the max of 8 doesn't seem to make much difference. Could be a bad controller like DHR says.

 

[Dead Horse Racing]

is it just that one "mode" that isn't responding or other modes also?

 

[glider]

Doc

Where did you run the ground wire to and is it grounded properly which would make the unit inop. if it wasn't grounded.