velella

hey guys, i have a 99gs300 na-t, running a FI/C, i took all 4 o2 sensors out so the ecu cant relearn cause it doesnt know what AFR its at, it was working fine for a while, but it seems to be changing the tune around by itself now. i am very confused, i tdidnt think it could do this?

fordsvtmfl

iTrader: (13)

welcome to my world (well used to be my world...now i have a haltech ) same thing happens to everyone...and then ppl will tell you all this stuff 2 do, and about 50% work 50% dont and they have to get a real standalone (which should have been done in the first place)

jcat_350

coming from the guy that was hell bent on making the FIC work

yeah, its the long term fuel trims in the ECU that screw you up. Guessing it was about 200-300 miles before it started running ****ty? maybe less? the factory ecu's programming tells it to change after a while to a set table of fuel trims as a conditional statement (meaning something like this: when time > some number of miles or days or whatever, compare current trim to trim table, if current trim = trim table, end. if current trim /=/ trim table, let current trim = trim table, end.)


this is why engineers get paid so much, especially lexus engineers.

ElitistK

iTrader: (4)

you need to keep at least one primary o2 sensors in the loop. it sounds like you're trying to do too much change at this moment.

or you can pull the coolant temp sensor, forcing the ecu to go into open loop.

Curry

iTrader: (1)

I had just posted on your build thread over at clubna-t. I wanted to know how things were going with the tuning.

tommyGS3

iTrader: (4)

i'm running all 4 sensors and it runs fine with my fic...i just need to replace one primary o2 sensor and my car will runn 100% with the fic....

fordsvtmfl

iTrader: (13)

everyone loves to deny it...but so far EVERYONE that ive seen or heard of making the FIC work on their lexus has a 01+...they all claim this has nothing to do with it....but until someone disproves me...im sticking with my theory that something is different enough about the 01+ to make it work, and not work on the 98-99 maybe 00

JeffTsai

iTrader: (1)

I have done several cars now that can run strictly on a FIC withouth throwing CEL's. It's all about how you tune it. You have to constantly check and tune in sync with what the O2 feedback wants in realtime. Then again, me being an EFI University Advanced certified tuner helps as well

velella

well jeff, any chance you can post up a tune so i can check it out and compair things to mine, i was running great for like 2-3K miles and than it started to change to the point i couldnt drive at all. i just wanna get this working correctly, and if i can get another tune, and use that as a base to help my car, that would be awsome!

velella

whats up with autotune? i dont think the FI/C has it, but i know like e-manage has it, and if were not using the o2 skew its not like the fic is that much different from the e-manage. i mean if were not using the main feature of why i bought it, and im staying at low boost, i can even run a safc and save the money from the fi/c right? but i am deff interested in an e-manage and auto tune.

JeffTsai

iTrader: (1)

I don't really like how the e-Manage works...more specifically the software interface is very clumsy. As for the FIC, are you telling me you're not using the O2 Skew function? If so then that's a big part of the reason why your tune is going out of whack every once in a while. Also, the FIC is different from the SAFC in the fact that it can clamp MAF voltage, and offset fuel injector duty cycle, in addition to retarding timing, and especially the O2 skew.

I don't have the maps because those tunes were for a few cars I tuned for other people. I might be building a new GS as a daily driver with a mild 350-400whp small turbo setup. I'll put a FIC on there and then I'll share the map once I get it dialed in and all.

velella

i wasnt using the o2 skew cause i get so many people saying do it different ways, i didnt know what one was the right one. if u have it working right, can just send me a link with the right way? if i can get it working im more than happy to do this stuff, i just cant go out spending money for a haltech and crap, i need to sell the car anyways since im getting in real bad money problems, so i need it working right to do that

velella

?...................

JeffTsai

iTrader: (1)

Sorry I don't have any maps on hand right now for the FIC. Also keep in mind what works for one car will not work for another car. There are too many variables to take into account. I could send you a perfect working map that is great and has zero problems on a car here and you can upload that to your car and it might still run like crap. For these cars, they have to be tuned individually and very specifically to what mods are on them. The reason being is that the ECU is extremely picky about fault tolerances...the slightest abberation will trigger a fault condition and possibly throw the engine into safe mode.

velella

no i was asking if u had a link or something to get the o2 skew working, there are 10 different ways people claim to get it to work than others say it doesnt, so since you said u had it working correctly i was just wondering if u could point me in the right direction for this.

i just did a basic install of the fic, didnt do the injector wires or anything, and pulled out all 4 o2 sensors cause it wasnt driving at all really with them. ideally i only want to use 2 of those stock o2's cause thats what my DP has for bungs.