I have a Gen3 DBW 6.0 with a 4L70, 80lb injectors on a Holley High ram. The car runs great and shifts really well using the data from Bluecat. The only issue is when I go full throttle, it will only go to around 3800rpm and hang until I let off the throttle a bit. Then it will shift and feel ok again.
I need some help finding the issue. Obviously I'm missing something somewhere. I welcome any constructive criticism.
(see log and tune attached)
Cylinder airmass is impossibly high for a naturally aspirated engine - the MAF & VE are unrealistic. Either it has no fuel pressure, or the MAF/VE were created by guessing, or the wideband is lying to you (or some combination of those).
Why 101-lb injectors on a N/A engine? What injectors are they and where did the data come from, and what is the fuel pressure (mechanical gauge, pressure reading while at WOT)?
You've zeroed out torque truncation for shifts, increased max torque vs rpm for the TCC, and enabled TCC shift lock. All rookie mistakes. The airflow models and injector data are wrong, so calculated torque is wrong.
The injectors are SEP 80lb EV1 (long). The data they sent is on my other computer, I can get to it during lunch. It's been a few months since I installed these injectors, but I believe I had to change/convert the Flow rate from using 43.5 lbs of pressure to 58 lbs because my regulator at the time was no adjustable. Since then, I have installed an adjustable pressure regulator, but did not want to retune at 43.5 lbs because the car was running great, except for the WOT RPM/shifting.Originally Posted by blindsquirrel
I remember having tons of rich idle issues at first, until I adjusted the "Minimum Injector Pulse" lower.
I'm guessing I'm going to have to adjust my fuel pressure down to 43.5 and start over with new VE and MAF calibration?
I have not witnessed the fuel pressure at WOT, but I do have the means available now.
To adjust the VE and MAF I used the "correction data" while driving, then Paste by percent into the tables. I adjust the VE first with the MAF failed, then adjust the MAF with the "Dynamic-High RPM Disable" set around 200rpm.
As always appreciate your input, thank you.
Should I just reset all of the torque reduction back to stock?
I will be revisiting the Injector data and MAF-VE calibrations.
Rookie mistakes made by a rookie for sure. That's why I'm in here learning as I go.Thanks for your help.
Yes. Start with stock settings then reduce a bit if you want. Don't disable it. Without torque truncation it's like a power shift in a manual where you keep the gas pedal down while shifting. Now, the TCC torque limits shouldn't be anything but stock.
As for the injectors post the data so we can review it for you. 80lb/hr@3bar is 92lb/hr. You have 101.3 lb/hr.
Attached is the Injector Data.
I really appreciate the help. If I recall, I input the data as-is, and it ran WAY too rich. I possibly bumped the Injector Flow Rate numbers up until the AFR came down enough to manage. My intentions were to go back and readjust, but ended up leaving well enough alone. Been busy this past year, but finally have time to investigate.
Looking at the DATA, it is presented as g\s on the excel sheet, so if I switch the IFR to g/s then paste the (LS2) data in, and switch it back to lbs/hr, I get 101.3 in the 40kpa slot.
A further look at the data turns out these are 101lbs/h injectors. This makes way more sense. I thought I was purchasing around 80lb/h injectors. No wonder I was having issues getting it dialed in.
Last edited by Mingus; 01-09-2024 at 02:05 PM.
Here. Setup for SD tuning. Go through the changelog to see what was done. There were a few mistakes.
You have to be careful buying parts like this.
They are considered 80LB/HR at 3 Bar but your running 4 Bar fuel pressure.
If you were to lower your fuel pressure to 3 Bar it would have been fine with 80# IFR in the tune.
The datasheet says the 'GM plug&play' tables are for 400kPa.
Yes. 58psi flow rating on the GM plug-n-play tab. If you look at the column headers you needed to use the LS1 values instead of LS2. That's what I entered.
Awesome! I'll look through it this evening. Thanks for the time. I'm guessing to switch back to Dynamic (with MAF) I would just put the High Freq fail back to 13500 and the MAF DTCs back to MIL on 2nd error? Then recalibrate the MAF with the High RPM Disable around 200?
I was switching intakes from an LS6 to the Holley High Ram, so I decided to upgrade the injectors at the same time. I wanted something around the 60-80lb to allow me to go with a turbo setup later down the road. These ended up being 101lb.
The log shows it missing on the drivers side.
Does it do this on the first time and then drives OK?
Have you verified it isn't loosing fuel pressure? It doesn't look like it is but it would be worth checking.
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That's right.
It does it almost every time I go wot. Sometimes, very rare, it will pull hard all the way through the RPMs and shift on time. I will put a fuel pressure gauge on it this weekend.
might be a ground issue if it cuts out completely. Flooring one with a loose ground often shows up like a total loss in power. Sometimes with a big backfire when it comes back online
Tuner at PCMofnc.com
Email tuning!!!, Mail order, Dyno tuning, Performance Parts, Electric Fan Kits, 4l80e swap harnesses, 6l80 -> 4l80e conversion harnesses, Installs
It's not cutting out, it's just hitting an RPM limit before getting to the shift point. My rev limiter is set to 6500. It goes up to about 3800 and hangs.
I had a similar problem a while ago. Might be related.
https://forum.hptuners.com/showthrea...ht=rev+limiter
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