I understand that Christo, that's what I said. It uses stored values from when in closed loop to calculate injector modulation.
Supercharger install
- Thread starter boydmick
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
I understand that Christo, that's what I said. It uses stored values from when in closed loop to calculate injector modulation.
sleeoffroad
Supporting Vendor
I think there are very few places on the fuel map where you can be in closed loop or open loop depending on circumstances. As I understand it, but I could be wrong, is that the open loop values are from a fixed map.
For example, under high RPM and high load, the truck will almost always be in open loop. So the fuel values for those cells will never be changed by closed loop fuel trim since you can not have those conditions (RPM & LOAD) while in closed loop.
For example, under high RPM and high load, the truck will almost always be in open loop. So the fuel values for those cells will never be changed by closed loop fuel trim since you can not have those conditions (RPM & LOAD) while in closed loop.
remember that when you guys say learned is actually not that acurate, since the computer is working with a O2 sensor that is no wideband, it's a narrowband and not that acurate.
Maybe i don't know much about toyotas ecu, but usually a normal ECU, uses open loop to get to operating temperature, after that everything is closed loop. Is anyone sure that toyotas are not like that?
Maybe i don't know much about toyotas ecu, but usually a normal ECU, uses open loop to get to operating temperature, after that everything is closed loop. Is anyone sure that toyotas are not like that?
With the addition of forced induction the values used for open loop on a NA engine would lead to a very lean condition. The ECU has to be adjusting for that.
When I was running hot this summer and pulling the camper in the mountains the truck seemed to run fine, idled perfectly.
I then corrected the hot condition and the truck immediately ran almost at 1000 rpms during warmup, an open loop situation, until the ECU corrected itself during closed loop. This process took something like 3 drive cycles and then functioned normally.
I'm confident that the ECU is using/referencing the last known closed loop values is some way when running in open loop.
When I was running hot this summer and pulling the camper in the mountains the truck seemed to run fine, idled perfectly.
I then corrected the hot condition and the truck immediately ran almost at 1000 rpms during warmup, an open loop situation, until the ECU corrected itself during closed loop. This process took something like 3 drive cycles and then functioned normally.
I'm confident that the ECU is using/referencing the last known closed loop values is some way when running in open loop.
sleeoffroad
Supporting Vendor
With the addition of forced induction, the mass airflow meter is seeing more air, thus giving the fuel based on that air metering. That is where the extra fuel comes from. The airflow meter is part of the sensors that feed the calculation of load. The fuel map is load vs RPM.
The ECU is not adjusting for that, it is just getting a different set of lookup coordinates to look at a different area of the map.
OK Christo, I think you got some penetration.
I still don't understand what was going on then during that hot drive. The truck definately responded from a long highway drive once the overheating problem was solved.
I still don't understand what was going on then during that hot drive. The truck definately responded from a long highway drive once the overheating problem was solved.
So as not to bog down this thread anymore, I am going to open a new thread with the discussion of the fuel map above. We kind of hijackd this one.
without a single wideband reading all this discussion may be wasted brain power. We don't have a single post with wideband data showing whats happening to a/f ratios of boosted 1fzfe's using the factory ECU. Please don't anyone start buying injectors and computers and other cool gadgets till this data is available. Scott why the hell hav'nt you done the data. you must have the equipment and you know this is true.
I was worried about leaning out with my motor after the turbo install so I baught a cheap narrow band which is useless for tunning but will let me know if things are lean. At WOT my gauge reads solid green (rich) suggesting im ok. I suspect I spend a lot of time running an open loop and am too rich which is costing me power. From watching my narrow band gauge I don't think my truck is leaning out. My egt has not ever got above 1600' so this is another reason I think I am ok. I have a supra pump. Is my narrow band telling the truth about the rich reading? I know I can not not offer any help beyond this without a wide band.
I was worried about leaning out with my motor after the turbo install so I baught a cheap narrow band which is useless for tunning but will let me know if things are lean. At WOT my gauge reads solid green (rich) suggesting im ok. I suspect I spend a lot of time running an open loop and am too rich which is costing me power. From watching my narrow band gauge I don't think my truck is leaning out. My egt has not ever got above 1600' so this is another reason I think I am ok. I have a supra pump. Is my narrow band telling the truth about the rich reading? I know I can not not offer any help beyond this without a wide band.
Dusty,
Your right, I do have the wide band. I also have an extra piggyback that I will eventually put on. My only excuse to answer you is that I have monitored the short term and long term fuel trims for quite a while and they have been suggesting that it has been running stoch to slightly rich this entire time. If my STFT was high (10+) while I was in boost without being at WOT then I would be worried. That would mean the computer was adding a lot of fuel based on what the O2 was seeing ie lean. STFT's and LTFT's mean nothing in open loop.
Also, a contributing factor is that I live at 4300ft. and regularly go up to 8000ft.
Less air less fuel, but you know that.
I will get to it that is for sure.
Building a turbo setup for the Tacoma has had me preoccupied but soon I won't have to travel for the job for the rest of the year and I can step up.
this discussion has been moved to this thread:
https://forum.ih8mud.com/showthread.php?t=116093
Post in this thread if you want to discuss the install by the author. The last two pages have gone another direction
https://forum.ih8mud.com/showthread.php?t=116093
Post in this thread if you want to discuss the install by the author. The last two pages have gone another direction
Done
