well i dont get it. ive adjusted evrything, been over evrything on my GSX (the beater car)
it has a horrid rich flat spot between 3500-4000 rpm. it has an AFPR, SAFC2, 550cc injectors, 16g @ 15 psi ,255Lpump,1g MAF lower honeycombs removed,K&N, cut airbox,FMIC on it now too.no boost leaks, not even the TB shaft. i have to set the AFC (hi throttle) at +5% at 3000, -18% 3600, then i have to jump to +5 at 4000 then to + 15 for the rest. that is the best i can get it to run, if i equal them out more it will go lean as hell at 3k, mega rich justabove 3k, then lean as **** again at 4kMy low points are all about 0 to + 4%besides bringing the idle back up for the hacked MAF. i started with my HI points there and it went to a 16:1 as soon as it boosted so i backed off quick. I had the easy driving part set fairly decent but open it up it goes lean.

i just dont get where this sudden rush of fuel comes from. Maybe i should reset my ECU and start over? it seems to come back if i adjust it out. And on a launch right as i let the clutch out it falls dead on its face rich and breaks up bad then when the turbo spools its hangin around 11:1 a/f. Could it be a fuel restriction or weak pump maybe over 4500 or so its not keeping up and its just pouring all it has at 3500 when the boost start pushing up the regulator? Mostly when the turbo isnt doing much its wanting to go rich so i lean it out with the AFC, i had to set my hi throttle point to 90% to make it stay rich enough under boost at WOT, yet rundecent enough to driveat any other part throttle to keep it away from the rich hi throttle settings. it it would just pour black smoke over 1/4 throttle and start missin like hell.
if i do it 30 / 80itstill goes way rich at 3500or so then it shoots to 10-12 psi leans out and knocks like crazy. then a little more throtte when it starts getting to the higher settings it richens up so bad it just about shuts off. so thats why i set the hi to 90%. its not the AFC settings that are causing the problem im just using it to help correct it and its not right somehwere else. no matter what i do for adjustment its gotta be extreme like 20% either way for different NE pointsin the 3-4.5k range. if i set it up for a place to start it just runs like total **** & jumps from really lean to really rich as the turbo start to spool then leans out again over 12 psi bigtime.
My base fuel pressure with the vaccum line off is about 37 psi. ive went up 10 and down 10 just to see what it does and the rich parts get worse higher, the lean parts get worse lower.
I'm leaning towards fuel starvation from a restriction or this pump is junk (replaced the fuel filter when i did the pump last week) I managed to hit fuel cut at 5000 rpm on 550cc injectors with a lean condition on the wideband so i know theres another problem. Fuel or bad MAF?
Sorry if im confusing and you have to read it 6 times over.[sm=sick.gif]
no boost = rich = leaning it out with AFC, --- boost = lean = +20% to richen it back up
I have not been able to monitor fuel pressure while driving because my gauge is at the shop. Im gonna check it out tomorrow probly.
If you made it this far in the post thanks for reading this confusing **** and hopefully someone will have a few tips. Just dont bash me for setting the AFC the way i did i been playing with it all morning and burnt up 3/4 tank of fuel trying and thoughts of blowing it up crossed my mind.[:@]

 

HOLY **** thats a long post, sorry to the unfortunate people who go cross eyed reading it[&:]

 

ok i did read the whole thing, really because its an interesting thing to come accross and i was intigued. .

OK so with the settings you have now you are saying that under full boost or right around when you hit full boost you get the jump in a/f. wow this is a mind blower. Well the +5 and +15 seem normal. Thats what you should have to do is richen a bit. What about maybe the map sensor getting screwed up. Just a thought, i doubt it would have an effect though.

or also another thing too look at, what are your air flow readings doing at that point?

 

airflow reading increase smoothly, and seem to go right with the airflow the engine should be taking in.
at 6500 RPM it jumps around quite a bit and its not even to 1800 Htz at the meter before correction. Dont you think +15 is a little much for 550cc injectors on a 1g MAF with just a 16g?I used + 19 with 450's and kept hitting fuel cut.I wish i could graph my a/f ratio vs RPM and all that **** just to show you, i suppose i would need to have DSM link for that.
But yea even at low throttle like just above 1/4 starting at 3k it seems to go lean, then it begins to spool the turbo from that, then the boost increases to 10 and it just goes rich as hell when the boost goes up intill it gets to 4500-4800 RPM then its like you flip a switch and pulls hard as hell. If i adjust the lean 3k rpm to richer it will run even richer asthe turbo starts to spool and takes longer to clear out because it only goes lean for a second just enough to cause it to bog, spool the turbo then it goes way rich as the boost starts in, 15 psi at 1/4 throttle and not accelerating is a problem, lol
Maybe my fuel press guage is wrong and i have it too high? should i try turning it down again and retuning. its a 1:1 rising rate AFPR with some jewish *** gauge on it. For all i know my pressure could be at 60 base if the gauge isnt right. I dunno i dont really have time to mess with it all weekend so i just wont drive it either, imagine that two DSMs parked in the garage and i gotta drive my s10

 

you could actually buy a pocket logger. Ive never used one but i know alot of people buy those when they are using a piggyback. Might be worth looking into. Anyway +15 might be alittle high. But every car is alittle different and i think an average would be around +8 so i dont think your really off.

Its a good possibility that the fuel pressure is off. Have you tried getting a reading when your at idle to see if its working correctly. You should get about 27psi at idle

 

at idle with the vacvcum line connected 28, without the vac. line its about 39 or 40. Is that right or wrong? Works great for my talon.
I'm gonna start over with the afc because i also found the recic hose for the BOV was kinked and that probly dont help my part throttle drivability at all if its blocking the air that should be going back in. I dont think the 30 / 80 throttle points work very well with this car but i just cant find that magic spot. I'm gonna reset the damn thing and the ECU thenstart over. I think the ECU is goin all over the place with the fuel curves and me constantly changing it is probly got it all whacked out.

 

Now that i think about it after changingthe turbo,FMIC,injectors, FPR, and pump i never reset the ECU so it still had the fuel curve in its memory from the stock injectors and whatnot. That could be why i have to take it to +50% to get it to idle and its still lean as ****.

 

Back on this topic i reset the ECU and now all my settings are in the -10 to -15% range to keep it 11:1 and it runs great. I started at zero , the first time i opened it up it poured a huge black cloud & shut off.
The ECU was all whacked out for some reason and was dropping the fuel to almost nothing at WOT.

I got the logger to work with this car finally & the fuel trims are 100-115% all the way across
Now that i got it tuned within reason i replaced the plugs, gapped to .028", seemed to clean it up even more so i had to richen the mixture 2%