First timer, won't rev, very lost...

[homedawg247]

Hi all, first time LS swap and HPT user here. I've gotten my engine running, but I have a weird issue where it will not rev past 1800, has no (meaningful) error codes, but idles fine and otherwise seems stable. I've noticed a lot of misfires on #2 & #7, but my coils seem to be working, my injectors don't look like they are doing anything weird, and my fuel pressure is not dropping out when I press the accelerator.

2006 6.0 LQ4 DBW
SM465 Manual Trans
Only have the front O2 sensors (B1S1,B2S1)
All EVAP unplugged and turned off

Only changes I've made in VCM Editor:
Disabled VATS
Set Trans to Manual
Removed lots of MIL


I greatly appreciate any help and insight anyone can provide. Please let me know if I need to attach any additional files.


6.0_Mod2.hpt
StillSkipping.hpl
FindTheProblem.Channels.xml

[2xLS1]

Disable all torque management. Starting with a real manual transmission operating system would have been a better option.

[edcmat-l1]

The narrowbands never come off zero. It is dead ass lean. If it does indeed have fuel pressure the calibration is off drastically. The trims go to +20% before going back to zero and even at +20% the Os2 haven't moved. I make sure you have fuel pressure first.

If it still does the same after you get your fueling figured out it's probably due to flipping the trans switch. As already stated you may need to start with a manual OS. But even if you do that your fueling is WAY off.

Yeah that PCM probably isn't going to place nice with the trans switch flipped.

Lean.jpg

[homedawg247]

Thanks for the pointers! This ecm is supposedly the one that came with this engine, so I'm not sure how the fuel would be so far off. I'm measuring fuel pressure before it goes into the stock fuel rail, and it doesn't move when I press the accelerator.
Could my O2's be wired wrong? My harness was hacked and I had to buy plugs and rewire a ton of connectors.

I'm happy to try a new OS, how would a find the correct one and flash that into my ECM?

[gtstorey]

How are you measuring fuel pressure,

[edcmat-l1]

It's not an O2 problem, they're reading correctly. They start around 450mv and go down to zero as they get a little heat in them.

You need to be measuring fuel pressure at the fitting on the rail.

A 2004 Corvette OS should work in that PCM. I'd do some research on the pedal number and throttle body first though so you don't brick it.

I'm not sure what truck OS is P59 DBW and manual trans. Someone else on here might though. If there is one.

[homedawg247]

How are you measuring fuel pressure,

With a manual gauge in a tee fitting right before it attaches to the stock fuel rail. I have an adjustable FPR at the tank I can increase and see if that richens the mixture

[2xLS1]

Are you running open headers by any chance? If so you can't do that with CL and O2 sensor feedback. And if you are using a 06 pedal, TAC and TB then you need to use a 06 or 07 truck MT OS. 06 ETC hardware doesn't play nice with earlier calibrations. They come in 4.8L and 6.0L versions.

[homedawg247]

Are you running open headers by any chance? If so you can't do that with CL and O2 sensor feedback. And if you are using a 06 pedal, TAC and TB then you need to use a 06 or 07 truck MT OS. 06 ETC hardware doesn't play nice with earlier calibrations. They come in 4.8L and 6.0L versions.

I am running open headers, just haven't gotten the rest of the exhaust connected yet. I can do that today and test again if that's messing up the sensors readings.

Where do I find the right OS to download? Can I save my current OS if I need to go back?

Thank you all so much for the help, I've been scratching my head for a week looking for error codes or something to explain this

[TheMechanic]

I have many stock OS tunes. I only have one with your OS but it is for a 4.3. Not sure if that is going to help. What say the crowd?

P59-2006-Silverado-4.3-Manual-12606807.hpt

[2xLS1]

A lot of parameters would have to be changed to make it correct for a 6.0L and not copied from a 6.0L auto file.

[TheMechanic]

A lot of parameters would have to be changed to make it correct for a 6.0L and not copied from a 6.0L auto file.

I have thousands of stock tune files but that specific OS looked like it was ONLY 2006

[homedawg247]

Ok, Thanks to everyone so far foe the pointers! I loaded a new tune without all the torque management stuff and it revved to almost 3500. I also extended the exhaust from the headers about 20" on both sides. My concern is the fuel trims are still peaking at like 26%. My fuel pressure gauge does not budge when I goose the throttle. I'm still getting a lot of misfires on #2 and #7, but I don't know why. The plugs are wires are brand new, I'm not sure hoe to test the coils without just moving them to a different cylinder and seeing if the misfire follows that.

If there's any more information or files I can share, please let me know. I appreciate everyone's willingness to jump in and give advice!



AfterTqMgmtRemoval.hpl
6.0_Mod2_DELETE_TqMgmt.hpt

[homedawg247]

Update, I found out injector 7 is not working, so that explains some of my misfire. I'll get a new injector(s) and get that fixed before I keep digging.

[TheMechanic]

Update, I found out injector 7 is not working, so that explains some of my misfire. I'll get a new injector(s) and get that fixed before I keep digging.

Misfires will give a false lean reading with and rich correction (positive trims).
As to your fuel pressure you didn't say if it was referenced return style or non-return. Also you didn't mention what that pressure was. 58psi?

[homedawg247]

Misfires will give a false lean reading with and rich correction (positive trims).
As to your fuel pressure you didn't say if it was referenced return style or non-return. Also you didn't mention what that pressure was. 58psi?

It's return style, back at the tank I have an Edelbrock 1728 FPR with return. I'm running a summit brand 255 lph in tank pump, and a gauge right at the rail to measure pressure. It still has the stock fuel rails which are supposedly internally regulated as well, at 58.5 psi. I'm reading 60 psi on my gauge right at the connection to the stock rails. I can bump this to 70 psi since it should get regulated down to 58.5 inside the rail. The rails do not have a return, they just dead end on the passenger side

[blindsquirrel]

A return-style regulator without a vacuum hose connected uses injector data set up exactly the same as a single-feed-line returnless system. The difference isn't if there is an external hose for fuel return to the tank or not, it's whether there is a vacuum reference hose or not. Referenced ('return style') or non-referenced ('returnless').

[homedawg247]

A return-style regulator without a vacuum hose connected uses injector data set up exactly the same as a single-feed-line returnless system. The difference isn't if there is an external hose for fuel return to the tank or not, it's whether there is a vacuum reference hose or not. Referenced ('return style') or non-referenced ('returnless').

Ohh, i do not have a vacuum reference hooked to the regulator. Can I run it like this or is it necessary to have a reference?

[blindsquirrel]

You can run it either way as long as the injector data is set up for it.

[gtstorey]

It's return style, back at the tank I have an Edelbrock 1728 FPR with return. I'm running a summit brand 255 lph in tank pump, and a gauge right at the rail to measure pressure. It still has the stock fuel rails which are supposedly internally regulated as well, at 58.5 psi. I'm reading 60 psi on my gauge right at the connection to the stock rails. I can bump this to 70 psi since it should get regulated down to 58.5 inside the rail. The rails do not have a return, they just dead end on the passenger side

Are you running a second regulator to regulate "down to 58.5 inside the rail"?