Going lean on top end AFR 19.5 WB !!!!

[RandyWS6]

:help: Can any one help me , On a hard run my AFR is starting out at (12.5 OL) and all of a sudden it jumps to (19.5 OL) it just started doing this the other day, before that every thing was working perfect as far as i could tell ,I'm trying to tune my self and don't know a lot about it, but i'm trying to learn,The motor is a LS2 418 cid.Ive changed the fuel filter and the fuel pressure is dropping down around 50psi i have a 255 fuel pump. You can see it in my log file at the end of the logging and i put my Tune files also if any body can help me with the tune ,i know there are mistakes but im learning. :frown:

1701

[Doc]

I would check the sensor it'self. I have multiple spares just for reality checks. It only takes a little bit of moisture on a LSU4 sensor for the pump cell to develop a hairline crack that will manifest it'self in the manner you are describing. Fine at ~ idle but, when you nail it; increase exhaust pressure backflow it "opens" the crack enough to read a high, lean reading. If you are really at 19 to 1 at WOT you should have a toasted motor.

[RandyWS6]

O.k. you can look at the log 0055.efi below and see . everything looks o.k. but the WB . I have a new WB senser and going to put it on today.
And another thing I'm not showing any KR's nether

[Doc]

I'll have to look after work. :frown:

[RandyWS6]

Thanks,I need all the help i can get. Not much hear in Kentucky:bawl:

[mr.prick]

is your fuel pressure that low at idle or WOT?
i had my fuel line in the tank come lose once and had very low fuel pressure.
do you have the MAF enabled?
i noticed your MAF table is stock.
i had that problem after enabling MAF for the first time,
i had to increase the whole table by 25%, then log and make changes .

[RandyWS6]

Yes ,im steal using the mass air ,its a SLP 85mm. My fuel pressure at idle is 63psi and at WOT it drops around 52 to 55 psi. Im steal learning how to tune ,dont know a whole lot a bout it, I found the problem with the WB going lean it was the sensor ,I put a new WB O2 sensor and my AFR dropped to 12.5 here is the log i made. Do you see any thing i need to tune or a just like timing or any thing out of balance

[mr.prick]

are you tuning your ve table?
what are you doing?
your logs are kinda short
also my filter showed you are still kinda lean in spots
you seem to have a mostly stock ve table for a stroker.

[joecar]

Regarding Log_0055:
- something is wrong with your PLX.
- 26 channels are used... to AutoVE tune use no more than 24 channels.
- at WOT the TP has downspikes about 0.3s wide, if you didn't do that then the TPS has a problem.
- MAP doesn't look right, you may have an air leak.

You have to do something about the drop in FP that you mentioned (50 psi), otherwise it won't allow you to get good consistent BEN's.

Regarding Log_0065:
- PLX AFR looks better in some places, but it still looks like something is wrong with it.

[RandyWS6]

I not done much at all with the VE tables ,because I'm don't know what I'm doing yet.Steal learning, I'm not doing AUTO VE yet nether, but hope to soon. The down spikes are from letting off the gas between shifts. Not trying to speed shift ,while i was having the false lean problem. I'm the only one around here at home with in a 100 miles that has EFiLive tuning soft wear that i know of ,so i don't get any help except on here, And most of you guys are pretty advance with this tuning stuff , And for me it hard to under stand . If some body around here at home knew how to tune i shore would let him tune my car and help me learn the basics.But for now it just trial and error's .Made another run but not to hard to see if the WB sensor fixed the lean spike ,i usually shift at 7200 rpm's and i'm going to set my injector flow rate down a little to being my LTFT's closer to 0. Below is the last run i make tomarrow ill will blow the tires off of it ,and post it up.

[joecar]

Ah, shifts, I missed that.

Go ahead and do this:
- figure out why fuel pressure drops so much (how did you measure it...?);
- check for intake leaks;
- use the spreadsheet to calculate IFR B4001 table for your injectors (which injectors do you have...?);
- reduce the number pids so that the number of channels is 24 or less;
- do AutoVE tune... after 2 or 3 iterations, if your BEN's fail to converge on 1.0 then something is wrong with your wideband or you have an airleak;

Your MAP shows that you have a cam, but at closed or steady throttle MAP wanders around alot, so there may be an airleak.

In post #10 did you mean to attach Log_0065 which you already attached in post #7...?

:)

[RandyWS6]

I have a fuel pressure gauge on my piller pod and my fuel injectors are SVO#42bls. The cam is a Crane Hyd.250/266-.650/.650-112 ,and the log file is the same ,i just forgot i put it on here last night. Ive done the spread sheet on the injectors but i need to lean it out a bit, Did you have a chance to look a my tune file?

[joecar]

I have been looking thru it and I didn't see anything bad...

For AutoVE be sure to disable closed loop and DFCO (explained in the AutoVE tutorial).

[RandyWS6]

O.K. thanks for helping me,Even use old guys need help some times :D I build my own motors but steal learning how to program them,building a one of these engines not to bad when you start looking at the turning to make them run to there pritchel. The engine fills strong but i believe there more there, if i can just learn how to tune. :help2:

[joecar]

Computer engine management is a whole new world... :bash:
The PCM/ECM is behaving like a combined carburetor/distributor (and a few other things)...:cheers:
The principles are the same... the means of tuning is different. :)