cr-rex

iTrader: (114)

https://www.rx7club.com/3rd-generati...1101940/page2/

that is my previous thread where i am "progressing" from. long story short, to fix my issue i had to make adjustments in settings 5 tab. i am using rc engineering 850/1300 side feed with a street port and a gt35r. below is the settings that were on the tune when i bought the car and when the previous owner had it.



below are the settings i changed it to and got VERY positive results


with these settings, i was able to lean out the idle afr to the 12s and get it to be stable. just like a normal car. driving around town and cruising on the highway was great. perfect even. the issue comes when i lean into the throttle and try to get into boost. the stumble i had before is completely gone now BUT when i lean into the throttle it gets super rich (10.0) then as boost builds it goes lean

i have a feeling that with the numbers i input that its doing this because i may have overshot what the numbers actually should be. i understood what i have been reading enough to get to this point but i dont understand it enough to know what to do next.

these are the threads i referenced for my information:
https://www.rx7club.com/3rd-generati...-right-900495/

https://www.rx7club.com/power-fc-for...maries-843507/

https://www.rx7club.com/power-fc-for...ion-ms-342723/

cr-rex

iTrader: (114)

so i went driving around last night and started experimenting... interesting observation that i am trying to find the answer to: the higher i set pri/sec transition % the more i can boost and stay in the appropriate afr. the ~8% difference between the entered value and the logged value is obvious now. i didnt quite understand it before. i played around with the lag times and the sec transition time and wasnt able to find a medium where it didnt just lean all the way out at the set duty cycle.

i attached a screen shot of the graph when the transition happens. i couldnt get the duty cycle to log and i think i figured out why. i didnt have the box for "basic" checked in the monitor window. i also didnt have my wideband hooked up the box. as this point, im going to call it quits and wait until i get the car to florida and take it to kilo for another tune

cr-rex

iTrader: (114)

just thought id post up a screen of the graph with the duty cycle. i also attached the log

arghx

iTrader: (3)

your wideband isn't reading correctly. there's nothing you can do with this log. The screenshot you posted clearly shows a flatline AFR reading and opening the raw data in Excel shows all the analog parameters and the wideband calculation to be stuck. injector duty cycle is irrelevant for this situation unless you have a fuel system flow limit. Maybe you are eyeballing the gauge in the car, but that's not sufficient to troubleshoot your problem.

Log only "Advanced" and "Aux" in the monitor window. Fix your wideband input. When you check every box it slows down your sampling rate. I didn't get a chance to look at your map because I don't have FC edit on my computer at work, so I don't have any comments on that.

When I see this situation it is a red flag to me. It tells me that you are missing some basic experience and skills needed to tune your own car, and that you are unable to recognize that weakness. You are reading a few threads and trying to apply them, but not seeing the big picture. This is a risky situation. You could blow your engine up. I don't mean any disrespect by this comment.

cr-rex

iTrader: (114)

i understand, no disrespect interpreted. i mentioned in my previous post that the wideband wasnt hooked up and no, i dont know what i am doing. i make no claim to know. i just got to reading whatever information i could find on the internet (not just here) and made an attempt to apply it as you stated. i have already called it quits since i feel like im skating a thin line with destruction being on the other side. i had to experiment with this since ive been troubleshooting for some time now and have run out of options. i had to be able to definitively say my problems were tune related and not mechanical. even though i dont understand why the previous tune is now trash when not much of anything was actually changed, i accept that this is the situation.

i just wanted to post all my data here for future reference in case it could be used for something by someone later on. i will be taking the car to kilo racing to get a re tune. fortunately through this, i was able to get the idle stable and get the car to drive normally outside of boost. that was my biggest goal. keeping it from flooding every other start is a win for me. its drivable now so long as i stay out of boost.

arghx

iTrader: (3)

ok cool. I see the part where you mention it's not hooked up, I must have overlooked it. Good luck with the car.

cewrx7r1

iTrader: (2)

I posted years ago about the crappy injector transition with the PFC. People use to change
Settings 5 injector overlap to make it better. But that did not really fix the problem.
With both stock 550/850 and my 550/1600 injectors the best transition was with 30% trans and .100 trans ms.

The PFC tends to keep the primaries on too long, when the secondaries come on they are too rich with the primaries dropping too much.

Log ADVANCE while boosting even at low boost until about 5000 rpm. Make a graph Inj Duty Cycle and Inj Fr Pri and Inj Fr Sec. Adjust your injector values for smoothest transistion.

cewrx7r1

iTrader: (2)

In my haste, the stock graph is really an in-between test.
Here is the TRUE stock test. It is even worse.

a.tapos

Id suggest either a newer ecu which will operate the injectors at a lower ms then a pfc,or go back to 550's(better option/runs like stock)

I know you can make them run on 850 primaries(ok for a bridge/higher idle) but they dont go lean enough for me,and when you adjust the settings to allow it it creates problems with the rest of the map and the correction/accel maps,

I spent a whole day trying it for a customer and it was a pain,got the idle to about 12.5 but it was not worth the effort.

cr-rex

iTrader: (114)

yea.... everyone has been telling me to go 550 primary. heres my....... reserve..... about doing that: i bought the car with the current injector set up and it ran and idled perfect. i did a "refurbish" of the engine and bay and now the tune that was on it is completely off. what im worried about if i put 550s back in is that there will be a large power loss when i go for a retune since im losing so much in injector size. what i dont want is to have to upgrade my fuel system to top feed injectors to make up for it. i know that the car will run fine with the injector set up since it was fine when i got it.

it made the trip from texas to florida to north carolina without a single hiccup or mishap. not to mention all the normal driving that was done while in florida. although the suggestion of swapping out the 850 for 550 is presented before me for reason xyz, i am going to remain with what i already have. the car has been just fine with what it has long long before i owned and i believe it will continue to do so after it gets retuned. if i were keeping this car then investing in a super nice fuel system would be cool but im not, so i wont. the next owner can do that if they so choose.

cr-rex

iTrader: (114)

for future reference... the ACTUAL problem has been found.

the fuel pump couldnt keep up with the demand and after doing the rewire, problem solved. im using a brand new denso supra tt pump. i cant explain why the factory wiring isnt sufficient but it just wasnt. this would explain why i could boost in higher gears as well. its boost but at a lower load and the pump could keep up. lower gear with more demand and it falls short. the "funny" thing about this is that i did the rewire in the course of me troubleshooting and it made things worse so i put it back to stock. its a bitter sweet victory since ive spent such a large amount of time troubleshooting when the whole problem was this. at least i know all the components in the engine bay work properly lol