Newbie needing help with SD startup/idle tune

[stev0n]

Ok, I read through this forum & watched videos on youtube of how to tune in speed density. I found injector data here for the new injectors & input it all.

On startup, it is running so rich that it will start missing. If I rev it up to, say 2k rpm, it will drop down to 300-400 & struggle to smooth back out to idle. The log I'm including is only maybe 1 minute long because even with the doors open, it filled the shop up with gas fumes. I believe I'm in open loop. AFR is set to 14.68. But commanded EQ in the scanner shows .85 & I don't understand why. My graphs are from Goat Rope Garage & the 1 bar Primary VE EQ graph shows SUPER lean at startup & idle below 1,000rpm. But if i give it a little gas, on decel the same blocks show rich.

I have only ever tuned the stock engine a few years ago & had it running great, but forced induction & cams, etc are all new to me. So this is a learning experience.

Engine Specs:
2001 corvette
LS1
P01 PCM
Siemens Deka 80lb injectors (The data I found & put in is for 50lbs of pressure which is what I have)
Vortech ysi supercharger
Brian Tooley stage 3 cam
BTR valvetrain
LT headers, X pipe, then straight pipes (no cats & no mufflers)
AEM 4110 wideband (reading lambda & connected to HPTuners through serial)
AEM boost gauge (matching the boost numbers in scanner)

I'm waiting on my 3 bar map sensor to come in before I switch to 3 bar OS & trying to get the idle & base VE somewhat decent before it gets here.

may 18 2023.hplcorvette may 18 2023 - 1.hpt

[stev0n]

I should add I pulled the plugs after maybe half hour total run time at idle trying to get it set up, & they were black & soaked with gas, so I replaced them all.

[tana99ss]

I should add I pulled the plugs after maybe half hour total run time at idle trying to get it set up, & they were black & soaked with gas, so I replaced them all.

Ummm your command is .80-.82 according to your eq table you're in the right spot. keep in mind you want to log when you're vehicle has reached operating temps.

Let the car warm up, log it then reply here. Im far from pro but ill be glad to look at it. First glance VE table is all jacked.

[SiriusC1024]

You're running open loop.

Ur car on open loop:
OL tards.jpg

The Open Loop EQ ratio table (Engine>Fuel>Open Loop>EQ ratio) is used, and it's being offset by the Initial Adder vs ECT table.

Keep track of this part you need to understand it. EQ ratio in the log is lambda λ. See the symbol next to it? EQ ratio in the tune is phi ϕ, which is the inverse of lambda. Lambda is AFR, phi is FAR.

λ = 1/ϕ

Let's take the example of the startup log. ECT = 75F, MAP = 75 kPa. The EQ ratio table returns a value of 1.2ish. Initial Adder vs ECT adds .25. So, commanded FAR EQ is 1.45ϕ. 1/1.45 = .69λ. Shortly after initial startup, lambda increases (FAR decreases) due to both the Decay Mult table and increasing ECT.

----------------------------------------------------------------------------------------------------------------------------------------

Engine>Spark>Advance:
- Zero out Catalyst Heating Startup Correction.
- Magnify the values of Overspeed and Underspeed to stabilize the idle. Something like [0,-2.5,-5,-7,-10,-13,-15,-15,-15,-15] for Overspeed and [0,0,8,14,14,10,7,5,2.5,0] for Underspeed.

Also, rethink your approach to modifying the VE table.

[stev0n]

Ummm your command is .80-.82 according to your eq table you're in the right spot. keep in mind you want to log when you're vehicle has reached operating temps.

Let the car warm up, log it then reply here. Im far from pro but ill be glad to look at it. First glance VE table is all jacked.

You're running open loop.

Ur car on open loop:
OL tards.jpg

The Open Loop EQ ratio table (Engine>Fuel>Open Loop>EQ ratio) is used, and it's being offset by the Initial Adder vs ECT table.

Keep track of this part you need to understand it. EQ ratio in the log is lambda λ. See the symbol next to it? EQ ratio in the tune is phi ϕ, which is the inverse of lambda. Lambda is AFR, phi is FAR.

λ = 1/ϕ

Let's take the example of the startup log. ECT = 75F, MAP = 75 kPa. The EQ ratio table returns a value of 1.2ish. Initial Adder vs ECT adds .25. So, commanded FAR EQ is 1.45ϕ. 1/1.45 = .69λ. Shortly after initial startup, lambda increases (FAR decreases) due to both the Decay Mult table and increasing ECT.

----------------------------------------------------------------------------------------------------------------------------------------

Engine>Spark>Advance:
- Zero out Catalyst Heating Startup Correction.
- Magnify the values of Overspeed and Underspeed to stabilize the idle. Something like [0,-2.5,-5,-7,-10,-13,-15,-15,-15,-15] for Overspeed and [0,0,8,14,14,10,7,5,2.5,0] for Underspeed.

Also, rethink your approach to modifying the VE table.

Thanks for the help! I haven't messed with the EQ table yet. Just trying to work on the VE table at idle. I see what you meant about the commanded EQ going to 1.0 at operating temp.

I drove the car down the access road in front of the shop today. About an 8 minute drive. Never got above 2,000 rpm as i didn't want to get into boost untio my 3-bar MAP came in (mailman just dropped it off).

Here is the current tune & long from the short drive around the property.

corvette may 22 2023 - 3.hpt may 22 2023 - 4.hpl

[SiriusC1024]

It's still running rich. If you insist on OL, then you should be tuning the OL tables with the wideband.

Why not use CL to correct fuel trims? PE should be setup to come online with boost.

Cruise around with closed loop to save gas and not wash oil off the cylinder walls.
PE engages when load demand increases to spool up the turbo then sustains through the run.

Turn your CL enables back on. Try it.

Ur car on open loop:
OL tards.jpg

[stev0n]

It's still running rich. If you insist on OL, then you should be tuning the OL tables with the wideband.

Why not use CL to correct fuel trims? PE should be setup to come online with boost.

Cruise around with closed loop to save gas and not wash oil off the cylinder walls.
PE engages when load demand increases to spool up the turbo then sustains through the run.

Turn your CL enables back on. Try it.

Ur car on open loop:
OL tards.jpg

will do. i'm still learning all this & was just doing it OL from all the tutorial that said to turn CL off.

[SiriusC1024]

You'll need to tune VE while PE is enabled by using the wideband. Tune with narrowbands for CL zones.

[stev0n]

3 bar map sensor came in. And when i changed over to the 3 bar OS in editor, I started getting a terrible hanging idle. If i touch the gas pedal, it will jump to 2,000rpm & stay there for several seconds. I have throttle cracker & follower disabled, & it didn't do this until I flashed the 3 bar OS. Also, I have the idle set at 830 across the board, but the idle stays around 900.

As for the rich idle, I realized the injectors are staying at 1.6 milliseconds, BUT i had it set at 0.59 milliseconds (changed it to 0.36 in the tune i uploaded but haven't run in the car yet).

Any ideas?

3 bar - corvette may 29 2023 - 1 - injectordata.hpt may 27 2023 - 4.hpl

[reubone]

Disable throttle follower and multiply your overspeed idle spark correction by 2