Lean/rich stumble bog solutions
Hi
I have read trough several topics in this forum about these lean or rich stumble/bog issues. However I have not seen many answer if the problems were solved or not.
What I would like to know how many have solved these issues and what did you change in your settings?
I 'm having the same situation in my 2x4 fitech. When I push the pedal slightly after deceleration my AFR jumps to 16-20 and it bogs. This happens in every temp. I tried to change accel pump higher, I have adjusted decel return fuel, dTPS acc gain and lowered my idle AFR without any effect. My IAC is between 13-16.
Thanks
Not a lot of solutions have been posted unfortunately. Myself personally have only needed to adjust Accel and Fast Accel to get mine running good. The data still shows an AFR swing, but within the limits of not hurting performance.
Now on a 2x4, if the primaries and secondaries are not synchronized perfectly, I would guess that could cause a lean tip in issue. With dual quad carbs, each barrel will balance the its own AFR as air flow increases. With Fitech the only proactive adjustment is the TPS. And the MAP and O2 are reactive.
The TPS triggers the Accel without any data of increased air flow. So, if there is a butterfly that is opening a little quicker than the others, air flow could exceed the Accel fuel.
Yes I also have this issue. It goes lean up into the afr 18 range just as you apply the pedal after coasting. I adjusted the accel decay setting and this seems to have made it a lot better and I don't have the stumble.
Quote from Shep69 on May 3, 2019, 10:59 pmYes I also have this issue. It goes lean up into the afr 18 range just as you apply the pedal after coasting. I adjusted the accel decay setting and this seems to have made it a lot better and I don't have the stumble.
Did you lower or increase these values? I tried to lower it without any effect. I also took off dfco cut like Austin suggested.
I'm just curious as I have never seen a 2x4 FiTech system in person.
How does it work with 1 controller?
Is there 2 TPS readings or is one throttle body the main source of sensor inputs?
What about the IAC? Does it use both?
What do the logs look like on a 2x4 system?
Quote from TTA Perf on May 8, 2019, 1:13 pmI'm just curious as I have never seen a 2x4 FiTech system in person.
How does it work with 1 controller?
Is there 2 TPS readings or is one throttle body the main source of sensor inputs?
What about the IAC? Does it use both?
What do the logs look like on a 2x4 system?
The second unit is just a slave. It has only 4 injectors and throttle blade adjusting screws. Nothing else. It's a power adder 1200 divided to 2 throttle bodies.
Do you have a log of idle and just some around town stops and starts?
Just this short log from cruise coast and accel where the issue is most irritating:
https://drive.google.com/file/d/1NqMmDlSWY7NJ7BC6sgTG-_VUieNqnGN2/view?usp=sharing
Disable DFCO and log again. Set enable temp to maximum.
DFCO was disabled during that log but here are couple new ones from today when I drove to work. Both cold and warm engine. Does the same thing.
https://drive.google.com/file/d/1n1dVhffunaQp5uq8O220lweQlWcqxIv-/view?usp=sharing
https://drive.google.com/file/d/10DgAzCLcLmQ03VaG0qQ7o7K-Xu5WfA7n/view?usp=sharing