VE table changes (increasing size)

[brian617]

VE Learn would be my guess. Have seen similar PIDs when using Snap-ON Modis.

[beestoys]

VE Learn would be my guess. Have seen similar PIDs when using Snap-ON Modis.

Eagle
Yes it is in closed loop.

brian
I be that's it I know the system is trying to pull out fuel. I am running 108 and the INT is hovering around the same 108 to 117 at the most. I know if I rest it with Scan9495 back to 128 it will stay that way for about 5 seconds then pull back to the 108. when it's at the 128 it's very happy. you can hear it dropping then compensate as it's pulling back down to 108. I'll do some more research in TP and see if there a corresponding flag or indicator in there.

I am now thinking I may go pick up an 02 sensor and drop it one side and see how it reacts. Because they are all getting pulled to 108 even during normal runs. I ran this thing for a quite a while with the speed sensor side disabled unawares to the effect it has on the fueling map. Trying to deduce without spending money until payday and the tinker gremlin in me. Can't leave well enough alone especially if I know somethings amiss.

[steveo]

no speed sensor on EE wont really screw your fueling up that badly, you just dont have a nice grid of BLM cells. it will still trim, just wont learn from its mistakes, so transitional fueling can be worse (it has to re-learn fueling all the time)

it's very common for closed loop to pull way too much fuel at low rpm on a modified lt1 because of corrupted o2 readings at low airflows. use your wideband to confirm that. if the trims are correct, when it's settling on 108 trims, your wideband should flutter around 14-15:1. if it's pulling too much, it'll be at least 15:1 all the time, or worse.

but if it's hitting 108 l-term trims with a stock-ish cam and exhaust and a stock-ish tune, there is something wrong. if the readings are legit, and those trims do produce a mean afr of 14.5-14.9 kinda thing, that probably means your ecm is out on its initial calculation by quite a bit. mechanical issue or botched constant, or something.

lets start here, what kind of modifications have been made to this engine, and what changes have you made to your bin so far? what bin did you start with? running SD or MAF right now?

[beestoys]

no speed sensor on EE wont really screw your fueling up that badly, you just dont have a nice grid of BLM cells. it will still trim, just wont learn from its mistakes, so transitional fueling can be worse (it has to re-learn fueling all the time)

it's very common for closed loop to pull way too much fuel at low rpm on a modified lt1 because of corrupted o2 readings at low airflows. use your wideband to confirm that. if the trims are correct, when it's settling on 108 trims, your wideband should flutter around 14-15:1. if it's pulling too much, it'll be at least 15:1 all the time, or worse.

but if it's hitting 108 l-term trims with a stock-ish cam and exhaust and a stock-ish tune, there is something wrong. if the readings are legit, and those trims do produce a mean afr of 14.5-14.9 kinda thing, that probably means your ecm is out on its initial calculation by quite a bit. mechanical issue or botched constant, or something.

lets start here, what kind of modifications have been made to this engine, and what changes have you made to your bin so far? what bin did you start with? running SD or MAF right now?

Ok here is the breakdown to get started with.
This LT1 is a 93 Camaro SS transplant. It now resides in a 72 Elcamino. The harness conversion on the first iteration was done by Zac at Speed Scene Wiring the newest iteration is upgrading to a 95 ECM harness again built by ZAC. It now runs the MAF and has sequential fire fuel injection. It has a Bailey LTCC coil conversion in it running NGK V power 55's gapped at .050. The intake has been port matched to a BBK 1000 CFM throttle body. It has the Cold Air Intake from the SS. Exhaust is Headman Elite shorty headers with 3 inch collectors. They dump into a TA performance 3 inch full dual system mandrel bent to the rear bumper. There is a 2.5 inch crossover and a pair of Flowmaster Delta Force 2 chamber mufflers. Drive Line is a 93 T56 6 speed.

I have reset the injector flow constants to match the 93 factory injectors installed. I have tried to use 93 low VE tables grafted onto the 95 tables to see if it helped the idle BLM's, no joy I also realized afterward the files were from a 5 liter not a 5.7 (they didn't help anyway but then I was only checking idle running so it may have not shown up then). The VSS input was not hooked up for almost a year but the truck wasn't driven except on an occasional weekend. There was a 6 month stint when my youngest used it to get back and forth to MMI. Other than that it's a stock 95 bin in there with only that one change. (injector constant)

I have wide band that will be going in hopefully this week. That way I have a reference to see if the factory 02's are shot. (they were replaced when I changed out to the 95 ECM) had to different sensors and wiring.

I also plan to make some more log runs now that I have some guidance on how to make a more accurate run. that way I can see if my changes I make in the future are helping.

Any suggestions or help in the meantime are very greatly appreciated.

[steveo]

the VE tables on your car will make a negligable difference with the MAF running. i have a suspicion they are used for some type of fueling calculation, but having an inaccurate VE table wont affect very much either way.

you need to be scaling other things. are the trims that far off across the board, or just at low rpm?

[beestoys]

the VE tables on your car will make a negligable difference with the MAF running. i have a suspicion they are used for some type of fueling calculation, but having an inaccurate VE table wont affect very much either way.

you need to be scaling other things. are the trims that far off across the board, or just at low rpm?

Steveo
I am thinking across the board. When I did a couple of log runs into work running a mix of surface streets at 25 to 55 and then freeway at 70 to 75 they all seemed to be the same. Now granted those logs were made with nothing disabled. EGR (is now and permanently per your guidance) PE and DFCO were running factory setup. I'll make another set of runs with those disabled under a more controlled environment per suggested methods I read by Eaglemark. Then see how it comes out.

I agree with you I have a feeling I have a constant out somewhere I just have to figure it out.
One thing I did notice yesterday while adjusting the IAC's.
They had gone to zero I though it was the BBK throttle blades being open to far. So I hooked up a Scan tool and adjusted the counts by backing off the adjuster screw. I got the counts back up in the 50's with a TPS voltage of .047. I then found out I had a vacuum line pulled that feeds my heater control circuit. Now the interesting thing I found was that the BLM's were up around 115 and 117. I hooked the line back up and they tanked to 108. I readjusted the IAC to mid 50's again with a TPI of .49. They are staying at 108 with the INT's at around the same maybe going to 117 but never higher. I know it's rich because every time I try to restart it I am very rich the truck will fire after a bit of cranking then it has to clear out.

So again I am figuring a constant is out that is why I have asked for a 93 5.7 M6 bin to look at tables and setting and maybe find something out there.

[steveo]

if it's affecting startup too, damn.

at this point, if you're confident that there isn't some kind of mechanical or sensor problem (which i doubt) just crank your injector constant till your BLMs are even, and go from there. try *1.05 or something to start with and see what happens.