Slo_crx1

iTrader: (9)

I've run into a little wall that's starting to get on my nerves lately, and for some odd reason I can't figure it out. I've been running the 9653 V7 Speed Density rom with an Omni 4 Bar map sensor for quite some time now without any major or typically minor hiccups, except for this one. I'll list a quick rundown of the mods and the symptoms:
'03 Evo/ecu, FIC 1050's/walbro 255hp pump, HKS 272's, 3.5" fmic/piping/all the typical turbo back exhaust pieces and a bit of custom 4-3" section to mate up to my Holset HE351CW turbo.

The problem I'm having is from a dead stop where I go to pull out into traffic or start on a hill etc. My AFR's will go from their steady 14.7 idle to the 12's as I press in on the throttle, but once I start releasing the clutch at around 1200-1500 rpm to move the car they jump to the 18:1 range and the car struggles to move. I can let off slightly on the throttle and it will richen up a tad (maybe into the high 16's) due to the ecu trying to maintain the 14.7 cruise range, but it makes things a bit dangerous when trying to pull out into traffic. Over the past 8 months or so I've gotten the map sensor set perfect, and even with the 1050's I have all my trims maintained at or under the +/-3% range. I've tried lowering the closed loop/open loop range for the TPS to try and read from the fuel map (which I've also lowered the values to the 11-12.5 range as compared to the factory 14.7 to no avail), and it still won't enrich more as I push in the throttle. I have my Asynch fuel accell table pretty well dialed in and runs perfectly during normal cruising, but I haven't touched any of the other tables that go along with the asynch table as I wasn't sure what they would do. I tried adjusting the delay time once and the car ran horrible, extremely twitchy and just plain dangerous in traffic.

Short of trying to run a full closed loop for lower rpm I'm pretty much stumped here, and I've run into the same issue while trying to tune my friend's SD swapped car as well. Any ideas/suggestions/help would be greatly appreciated!
Thanks!

l2r99gst

iTrader: (2)

Posting up your VE tables may help troubleshoot it, if it's in the tune. You don't have a 1:1 map VE table by chance, do you? It sounds like you are getting enough fuel when getting to the 100-120 kpa range, as compared to your idle conditions.

What I would do is maybe make a 3D chart of your total fuel trim correction (LTFT +STFT...lo for idle, mid for cruise) as the data for map vs RPM from a nice big log crossing through that trouble spot several times, so that you can pinpoint what is going on. That will also tell you if your VE tables need tuning and where.

95630706

I have precisely the same issue. It seems to get worse when IAts and coolant temps are high.

I will post screen shots of my SD set-up in a bit, and yes, I currently have MAP/KPA 1:1 until the very bottom 2-3 cells.

I was going to go after it in the acceleration enrichment tables so I'm very interested in this conversation.

ziad

iTrader: (1)

i have the complete opposite problem. i go super rich (under 10s) for a little bit on lift off... which destroys my trims. like the injector does not cut fuel on decel (the 4 decel tables) have been wound back a fair bit.

l2r99gst

iTrader: (2)

I asked about the 1:1 map VE, because I highly recommend against that because you won't be able to compensate for issues like this.

You need to change the compensation for a low map, where the throttle is barely open, to a larger map, where the throttle is being opened more to accelerate, but not yet in boost. Basically (in terms of a boost vacuum gauge and terms), you need to have very different values for 0 psi than you do for say 10 in vacuum.

If you have a 1:1 map VE table, you're telling your ECU when I am at 2000 RPM (just using that RPM as an example), give me the same fuel whether I am cruising or just when I mash the throttle to accelerate. Your MAP VE values around this 0 psi mark (100-120ish kpa) need to be much greater than your lower map values like 30-50 kpa (you can find out exactly what you need by making 3D charts of your trims). This is why a 1:1 map VE will not work. I would venture to guess that both ppl in this thread could resolve this with a proper VE table setup.

03whitegsr

iTrader: (8)

I've noted the same issue numerous times on here, I'm just glad others are starting to see it too as it is a major problem and I do not believe it to be a tuning issue.

While testing out some things though, I think I may have found something related to this issue. Unfortunately, my rear diff decided to start making a crap load of noise so I can't test it any further.

If you are brave and don't mind testing and possibly retuning the whole car, I have some information that might lead to a solution. If not, I hope to have my car up in the next couple weeks and will pursue it on my own.

ziad

iTrader: (1)

send it to me mate... i am going for a full retune from scratch (including a BISS Reset)

95630706

Here's my set-up... Works pretty good except for the above mentioned complaint. FIC 1100s, other Mods in sig...

Trims: LTFT low: 1.4
LTFT mid: -7.93

qnz

iTrader: (7)

And I thought I was the only one with the problem. Everyone says its the async vs tps delta table but I have added 5, 10, ant 15 points to the table and it hasnt gotten better, (or worse).

EVO8LTW

iTrader: (41)

The leanness when you are clutching out and starting up can be solved by simply altering the fuel table in those load ranges. On my car it was around 70-80 load and about 1250-1750 RPM. It's not an asynch issue.

the_mork

iTrader: (1)

What fix are you using? I was having some weirdness with fix #2 which I can only assume would likely happen with fix #3 as well. After going to fix #1 things are better.

I can only assume I'm running into a similar situation because I have an automatic but at low rpm and mid tps I used to have a pretty ugly lean spot that has gotten better.

03whitegsr

iTrader: (8)

In my experience, the lean issue existed regardless of engine temp or IATs. It only impacted driveability when the car was cold though. It seemed like when the car got above about 40C ECT, the car could drive right through the lean spots, but it was still lean.

scheides

iTrader: (10)

Hey man!

Please see step 6a, check your fuel map, it's a prime candidate for this! Try it and let us know

https://www.evolutionm.net/forums/ec...ched-roms.html

scheides

iTrader: (10)

Oops, I noticed you said you tried that already. Try going richer still, just for giggles. I think a combination of that (11's are probably fine honestly) and lowering the low-load, right-hand side of your MAP VE table (lower 33 to 25, 41 to 34, and 49 to like 39...maybe 59 to high 40's). I know you want a 1:1 MAP VE but for whatever reason, in the real world, it just doesn't always work.

GotWheelHop

iTrader: (39)

You know something, when I ran the initial 96533706 V7 romID, I never had this issue(no IPW dropout fix). When I went to the latest variant that had the IPW jitter fix, I started to notice the same issue as the OP. I will switch jitter fixes in the morning and see if there is any difference.