LS1 on Boost leaning out under Hi-throttle (log file attached)

[LS1 240sx]

Hey guys, I had another thread on here about the car not getting spark and fuel well that been taking care. the car is a 240sx with a :

LS1 shortblock
317 heads
120 lbs injectors
aem injector driver
E85 gas
76mm turbo
3 bar map
No MAF
Stock cam
acdelco iridium spark plugs



The car idles fine, afr at idle is 11.3 afr. when i drive its fine the second I try to smash the throttle and chokes and the wideband goes leannn. In my log file you will see when TPS goes past 50ish% rpms dont even climb up. If anyone knows anything im missing here or need to adjust anything, its well appreciated.

Heres my log file and tune, any inputs well appreciated. Thanks

[jimmyblue]

You should post a .cfg, I can't see wideband or a lot of what I'd expect you to be logging, since my defaults are not for your platform or OS.

[LS1 240sx]

You should post a .cfg, I can't see wideband or a lot of what I'd expect you to be logging, since my defaults are not for your platform or OS.

Where would I find my .cfg file?

I have a aem wideband but I dont have it connected to mpvi controller? I can make a video if you want.

[Bill@HPTuners]

Getting a more realistic VE table would be a good starting point even for just idle, if you are running with no front or rear o2's I would just set the tune up for open loop so you can rule out any corrections there as well, also looks like the IAT is reading -38F so you'll want to get that fixed as well.

[LS1 240sx]

Getting a more realistic VE table would be a good starting point even for just idle, if you are running with no front or rear o2's I would just set the tune up for open loop so you can rule out any corrections there as well, also looks like the IAT is reading -38F so you'll want to get that fixed as well.

I have no Iat sensor. Is there a way to eliminate it?

[Bill@HPTuners]

No, I've seen the pcm do alot of weird things when its NOT there, so that would be one of my first orders of business.

[LS1 240sx]

No, I've seen the pcm do alot of weird things when its NOT there, so that would be one of my first orders of business.

Ok, Which Ls1 came with external IAT?

[Bill@HPTuners]

All f bodies

[LS1 240sx]

Put the iat in and its muchhhhhh better, but the lean hiccups are kinda still there, especially when I try to go in boost like right around 1 psi it just pops HARD like backfire. Spark blowout? or timing??

[Nitroused383]

Um... for real is this a joke? I found your problem, you ever seen a fueling table composed of only 2 different values?

[LS1 240sx]

Um... for real is this a joke? I found your problem, you ever seen a fueling table composed of only 2 different values?

You have one I can use to start off with? Until I didnt change that 100 to 125 and put a IAT sensor in the car would go flat lean and choke as soon as I would step on the throttle. E85 loves to sip.

[killer96z]

Omg lol start with the help file in vcm suite. It will guide you on how to get a starting ve table...

[Nitroused383]

Start with a stock ve table since you have stock head/cam. Copy the 105 kpa row and paste it in the 315 kpa row. Multiply the 315 kpa row by 2.25 now interpolate the 315 row and 105 between vertical bounds. It will look like this, this is your fueling table and there is no way VE is 100 any time you touch the gas.

I included a stock 2002 tune so you can copy the entire 0-105kpa VE table. This is only a basealine you need to dial the table in with a wideband.

[LS1 240sx]

Start with a stock ve table since you have stock head/cam. Copy the 105 kpa row and paste it in the 315 kpa row. Multiply the 315 kpa row by 2.25 now interpolate the 315 row and 105 between vertical bounds. It will look like this, this is your fueling table and there is no way VE is 100 any time you touch the gas.

I included a stock 2002 tune so you can copy the entire 0-105kpa VE table. This is only a basealine you need to dial the table in with a wideband.

Thank You nitrous, I remember reading this in the help section but some reason I totally forgot about that method. Sometimes ppl just need a refresh. Once again thanks.