6.0 LQ4 stalling when @ operating temp coming to a stop - HELP!!!

[Capt.Throttle]

Have searched all threads similar to my situation and not finding solution. When @ operating temp and shifting into gear or coming to a complete stop, the engine stalls. I can over come the stall by shifting into neutral and coasting to stop and then by modulating the accelerator pedal prior to shifting into gear before pulling away from a stop. But this is a PITA. PCM was professionally tuned on a Mustang Chassis Dyno with a Wideband, but the provider hasn't really been helpful at this point (not ready to call out the shop unless this is a stupid simple fix that should have been addressed by the tuner knowing my build specs). FWIW...I witnessed the tune session and the issues I am having on the street were not observed on during the dyno tune. Not sure why the symptoms showed up later.

Build: LQ4, Truck Norris Cam, 243 Heads, Hooker LS Cast Manifolds, Full Length Exhaust, TH400 Manual Valve Body Compression Braking ALL Gears, Custom Hughes Torque Converter ~2100 Stall, NO VSS.

Note...VSS is not an option for me at this time, as this is primarily an off-road truck with a modified NP205 Transfer Case. I know a VSS solution exists, but refuse to accept that VSS is the only way to solve this. There has to be something in the tune that can fix this. Carburetors don't need VSS to idle in gear and come to stop right?

Tune and Log Attached - Stall @ 7 minute mark.

[SiriusC1024]

The VE table hasn't been adjusted correctly.

Actually, none of the critical items have. Professionally tooned.

[Alvin]

This tune is pretty poor.

The VE is exceptionally rough. The fuel trims are all over the place. - Most idle issues are actually fueling issues. So this isn't a nit picking thing.

Also idle timing is far to high leaving no room for reserve torque. Something around 18 degrees, going up to almost 30 in case of a stall would be much better than always sitting in the mid 20's.. No where to go should the idle dip.

There is enough rough work in that to go back to stock and start over. Sorry.

[gtstorey]

but refuse to accept that VSS is the only way to solve this. There has to be something in the tune that can fix this. Carburetors don't need VSS to idle in gear and come to stop right?

This doesn't really mean anything. You only have control of a small portion of the tables and codes on a stock ECM through most tuning software and sometimes you have to live with whatever the ECM insists on getting.

I'm not weighing in on whether the VSS is needed on this, just commenting on the fact that not everything can be fixed or worked around by the tune.

[blindsquirrel]

No carburetors don't need VSS, the smog-era carbs had dashpots instead. If you are so hostile to electronics maybe you should convert it to dual (er, quad?) VaraJets from like a '81 Citation. Those come with the dashpots already attached.

[Capt.Throttle]

No carburetors don't need VSS, the smog-era carbs had dashpots instead. If you are so hostile to electronics maybe you should convert it to dual (er, quad?) VaraJets from like a '81 Citation. Those come with the dashpots already attached.

Never suggested hostility toward electronics. Simply looking for solutions that work with my current setup.

[SiriusC1024]

What injectors are those? Vacuum referenced reg?

[Capt.Throttle]

What injectors are those? Vacuum referenced reg?

ACDelco 12576341 42lb/hr injectors; Corvette LS1 Inline Fuel Filter Regulator; Walbro GSL392BX 255lph in tank fuel pump

[SiriusC1024]

Octane in the tank and plug type?

[04silverado6.0]

You can try this. Not from a exact setup but should be much better than what you had. Reset ltft before starting.

[Capt.Throttle]

Octane in the tank and plug type?

91 Octane / NGK Spark Plugs TR5IX / OEM Coils / OEM Wires

[SiriusC1024]

Ok. Here's this if you want to begin fixing it. Clear LTFT's through scanner then log. Include Idle Adapt (STIT) and LTIT.

[SiriusC1024]

Looks like 04silverado6.0 put together a decent base for you, too. Either one works. Many similarities between mine and his. The takeaway is that there's a correct way to tune then there's whatever the hell that 'pro' passed off on you.

[Capt.Throttle]

04silverado6.0 & SiriusC1024 - Thanks for the tune files and guidance. I will load one of them up this weekend, get a datalog, and then post an update.

[04silverado6.0]

I believe my ve table should be pretty close. A lot better than what was in there.

[SiriusC1024]

Same

[RDF1]

Carburetors don't need VSS to idle in gear and come to stop right?
.

Carburetors are not a simple crude fueling contraption most folks think they are. But if a carb is setup poorly it will do the same thing your having problems with for the same reason.
Your PRO tune is quite beginnerish looking. You paid for a dyno tune and not a street tune?
Dyno is good for finding max power if done correctly. THen its time for street tuning to work out all these small issues.

[04silverado6.0]

I think the guy skipped steady state ve tuning. Having a mustang dyno it would probably take roughly a hour to sweep through the ve 3-5 goes.

[Capt.Throttle]

I think the guy skipped steady state ve tuning. Having a mustang dyno it would probably take roughly a hour to sweep through the ve 3-5 goes.

Burb was on the roller for about 2 hours. There was a lot of idle time, 4 or 5 low speed pulls from idle to maybe 2500 RPM back down to a stop and idle, then 3 or 4 WOT pulls in 2nd gear. I forgot to mention in my build specs that behind the TH400 is an NP203/205 transfer case, then a Corp 14 with 4.88 gears, and 40 inch tires. Final tune dyno sheet is attached, however the layout is garbage because there are no RPM units across the horizontal axis and no HP/TQ values on the right axis.

burb_dyno.jpg

[04silverado6.0]

With the non electronic trans it would be more time consuming to dial in without converter lock in the scanner. Probably had a glitch with the tach, i have some vehicles do excellent with my tach and some do not. Anything from electrical noise to a bad plug wire or weak coil can cause the tach to hiccup even if the engine runs good. Those numbers may not be bad considering the older software version being used.