Chasing My Tail

[NobleTech]

Well, I received this 1967 GTO with what was supposed to be a built 5.3 ls, headers cam and I have no info from the customer as he bought the car as is and the engine builder/tuner will not respond to any of his requests.

I'll post the as-received tune and data logs here.

it is really crazy that this car even ran, it's on the dyno now and it's short and long terms at up to about 35%
there is only one VE table and it is a diagonal flat plane.
it appears to be just running on the MAF
the injector data is incorrect judging by the part numbers on the injectors - 25326903
so I downloaded this 1166898781 file from the repository, I believe it was from a 2000 Camaro
I did however try the injector data from a 03 Tahoe with 24lb injectors and it was idling at 11;1 so I went back to the Camaro injector data, I thought initially these were 22 lb injectors, but now I can not remember.

I'll get to the point, whether I tune in closed loop or open, the error is about 15% at or near idle.
I change the VE and/or the MAF and it still comes back with - taking more fuel out, seriously, like 15% again
I have failed the MAF
disabled LTFT
and put 284 f wherever I thought was causing the stft to stay active. no luck
so I just stopped then with the scanner's vehicle controls
I lock it in third and lock the torque converter, and drive at part throttle on the dyno held at 1600,2000.2400 rpm's, and so on.

can someone please look at these files and report to me where I have gone wrong

I am willing to pay for help or for someone to log in and do a remote control session and clear this up

[edcmat-l1]

You're logging way too many pids. You need to cut most of them out.

Looks like the injector data is incorrect. Need to pull a file off the repository that matches your vehicle and copy over everything to put it back to stock. Then pull another file with the correct injector data and copy that. Then start your process.

[blindsquirrel]

That number crosses to L59 flex injectors? Which are supposed to be 35lb-hr at 58psi?

But I find it odd that with a problem like you're trying to solve, the rail pressure when you checked it with a mechanical gauge wasn't ever mentioned... so I'm wondering if somebody didn't think it was important enough to mention maybe they also didn't think it was important enough to check?

[NobleTech]

That number crosses to L59 flex injectors? Which are supposed to be 35lb-hr at 58psi?

But I find it odd that with a problem like you're trying to solve, the rail pressure when you checked it with a mechanical gauge wasn't ever mentioned... so I'm wondering if somebody didn't think it was important enough to mention maybe they also didn't think it was important enough to check?

yes sir, it is at 60psi, steady through all loads

[NobleTech]

You're logging way too many pids. You need to cut most of them out.

Looks like the injector data is incorrect. Need to pull a file off the repository that matches your vehicle and copy over everything to put it back to stock. Then pull another file with the correct injector data and copy that. Then start your process.

YES I AM, I was looking for a PID that might point to a solution, it's funny if I log one more PID the entire trace slows way down. LOL.
just learning this stuff on HP tuners. I wanted to see what does what.
also, what is a L59? As I say, I am learning, new to GM and HP tuners
just finished a Jaquar with an L59 flex fuel Tahoe. see the image, these are not 35 lb injectors? True?
also, I looked at a couple of other '02-'03 Tahoes with flex and the numbers are different some are 33 lbs/hr in all cells.
so, I would consider the 35lb
injectors mentioned here would be at 58 psi. so, they would be less at 3 bars? true?

Screenshot 2023-11-16 184511.png

[NobleTech]

also, just found this tidbit

states that the 33lbs is at 50psi or there about because the flex fuel trucks have a return fuel system and we are at 58psi with a returnless, apparently there is an HPT's calculator (where is it?)
first I've heard of this.

https://forum.hptuners.com/showthrea...6903-flow-rate

[blindsquirrel]

2005-up L59 files already have the injector data for use with 58psi returnless/nonreferenced. Just copy and paste the 4 tables.

[blindsquirrel]

L59 means flex fuel 5.3L with 'Z' as the 8th VIN digit.

https://en.wikipedia.org/wiki/GM_LS_engine

[NobleTech]

2005-up L59 files already have the injector data for use with 58psi returnless/nonreferenced. Just copy and paste the 4 tables.

Shazam, finally

I searched 12 vehicles to find one with Flex-enabled

does this look correct?

Screenshot 2023-11-16 200948.png

[blindsquirrel]

You should be checking the VIN shown in the 'Tune Details' tab to ID the engine. If it has a Z as 8th digit it was built with all the L59-specific parts, even if flex is not enabled in the file.

And 'injector data' means all 4 tables, not just flow rate.

screenshot.02-05-2023 19.22.51.png

[SiriusC1024]

As well as Transient>Min Fuel Qual. Take min injector pulse and divide by 31.2.

[horsepowerguru427]

Why 31.2? Transient fueling is something i read up on for quite a while months ago. I find transients to be very interesting....

As well as Transient>Min Fuel Qual. Take min injector pulse and divide by 31.2.

[weinerschizel]

I swapped in the L59 / Flex Fuel injectors into my LQ9 build. Assuming that's what they did with the 5.3L... The LM7 & LQ9 have same 24# injectors (Don't know of 22# Gen III SBC injectors) so if you have a LM7 setup then this scenario this may help.

Also they made two fuel rails if you have spacers on your fuel rail (between rail and intake) chances are they did what I did. Another note, the early model L59 has a return (if I'm keeping that straight). They have the same plumbing, just ever so slightly different pressure and Flex / L59 setup has higher flow injectors. This was the case with my 2002 baseline I pulled from below and my 2001 LM7 setup I swapped into a LQ9 build.

My current tune LQ9: 13 2023-11-11 263109 PE tuned, RTT OS, MAF DISABLED.hpt
L59 Baseline: 2002tahoeFlexFuel.hpt

Also with narrow bands that far off, I'd assume they're essentially out of their range to read. Did you verify with a wideband? Probably so but I didn't see that detail in your post?

I had copied these settings and seemed to work for me...

Flow Rate vs KPA
Flow Rate Mult vs Volts
Offset vs volts vs VAC

[NobleTech]

OK, guys, this is seriously crazy,
1st
I never mentioned that I did not need a license to edit this file
yes, most of the changes I make stick, and the feedback is correct, such as ignition timing and idle control
however,
some of the changes do the opposite. in other words, when I take away fuel from the VE table or the MAF table, the response is the opposite.
3rd
I upgraded the operating system to RTT MAF enhanced.
I then tried RTT and the response was no change at all,
so I copied and pasted by half in the editor and flashed the PCM.
the response again was the opposite of the changes
4th,
so, I think that the original engine builder tuner (who we can not reach) used something other than HP tuners to modify this ECU.
5th
with his tune as I received it, the car makes about 280/290 HP/Trq (this engine is built with a large cam, I have no info.
with the changes I have made it makes about 440/450 HP/Trq I added a bunch of timing and took a bunch of fuel out.
6th
the car runs pretty well, but a little fat on the dyno with the MAF failed. the AFR at wide open throttle throughout the RPM range is about .85-.83
when I un-fail the maf and try to tune the maf table, things start going opposite.
7th
the test 1st test drive on the street proved to be very successful in driveability, shifting, and closed loop control, however, it is still pulling about 10-12% fuel out at cruise with the MAF active
the real issue is, at WOT, the car bogs and is running at about 10 or lower AFR
8th,
So, I said, let's try a completely new flash, I can not write entire, It does not ask for a license until I try an 02 Tahoe with flex fuel.
so, I tried a vin swap and that went into the tune, but the PCM will still not write entire.and does not ask for a license.
it did write entire when I did the RTT/MAF upgrade

should I just get a new PCM and start over

[edcmat-l1]

Post tune files and data logs. Doesn't matter what was used before to edit the ECU. If you can edit it now with HPT, that's all that matters.

It doesn't have a bad ECU. I'm sure the issue is user error.

[NobleTech]

I am sure it is a user error.
That's why I asked if someone could do a remote tune for me and this customer.
attached are the file that is in the PCM now
and the last three logs so you can see the changes going the wrong way
I'll also attach the file with the changes.
and yes, I know I am logging too many PID's
Thanks, Troy

[NobleTech]

also, I just let the IAT cool down as it is one of these DIY cold air intakes behind the radiator,
I did a log with a WOT pull again. the correction factors are pretty close here. except at WOT. I'm still way too rich.
attached is the log

[edcmat-l1]

I email tune every day. I can be reached through my email in my sig.

[edcmat-l1]

I am sure it is a user error.
That's why I asked if someone could do a remote tune for me and this customer.
attached are the file that is in the PCM now
and the last three logs so you can see the changes going the wrong way
I'll also attach the file with the changes.
and yes, I know I am logging too many PID's
Thanks, Troy

That's a lot to dig through.

I can tell you by the names of the files it sounds like you're making changes in the wrong direction.

RTT 1st run way too rich
RTT 2nd run no response to ADDED FUEL.

[kevin87turbot]

Oh my! The only time I've ever run that much advance in an LS engine was in some NHRA Stock Eliminator cars!

The injector flow rate is still jacked up as well...that's why it's so rich.