14burrito

The point you are trying to make is a result that's directed towards engine speed more than tstat close/open flow through - IMO. Quicker engine speed will flow more volume with a lower delta. Slower engine speed will result in a higher delta but less volume. Thermostat is a floor to start cooling. Delta itself depends on efficiency of the system based off set variables. Again, this is my opinion.

Could someone who has factory fogs shoot me a DM please, I'd love to get a quick pic of a connector under the hood. I'd be very much appreciated!

Thanks, The speedo/odo being off is obvious and basic handhelds provide that option to recal. The PT sides makes sense, but it caught me off guard that I never did anything prior to on my Toyotas and the shift profiles, general PT behavior remained pretty on point before/after.

The way it reads to me: they were diagnosing rich running, found the high pressure pump leaking into the engine (fuel leak under the hood). That's why I was curious about more details. If the high pressure pump was over/under supplying I would be led to believe that the fuel rail would register a fault for low fuel rail pressure or rail pressure too high. I'd be suspect of the injectors leaking or sticking. What codes was he getting? Bank 1 or 2 rich? Then he could just swap injectors between banks and see if the rich running condition follows the injectors. (Providing he doesn't have a flaw bench) Rich condition only registered at start-up? Injectors could be bleeding causing excess fuel upon engine start and the condition rectifies once fuels burned. Etc etc I'm curious more details.

To a certain extent I can agree. But I also respectfully disagree as my fuel economy us upwards of 10% better in tow mode during daily use. Engine load. I see, both see via instant and result via tank, that tow mode puts me in a better part of my power band during driving. Sure my RPMs are higher as a result if a lower gear being chosen, but engine load plays a role as well. It appears that being at a slightly higher RPM reduces my engine load enough to get into V4 and stay in V4 much longer. Of course, driving habits and characteristics play a role and this may or may not be the case for you.

Stock tire size with no plans to go larger. *maybe one aspect ratio up* AFM activation and fuel economy in general is much better in tow mode which is part of the reason for wanting to regear. Genuinely feel 3.08 is too high IMO.

Hello Group, Looking into re-gearing the Tahoe 5.3l 4x4 mom mobile from 3.08 to a 3.42 to get into a little better torque curve. I have read through quite a bit of threads about gearing, sizes, cuts, 9.5 vs 9.6 etc, etc but one thing not mentioned was tuning. I just got off the phone after chatting with ECGS and the closing statement from them was, I have re-geared Toyota's in the past and within the Toyota community, tuning after a re-gear is far and few discussed, mentioned or even thought of. What is so special about the GM platform that the closing statement from East Coast was to make sure to get the TCM tuned after a re-gear? I can understand the notion to ensure the tire size calibration is set properly... On gearing topic, Likely going to just run some AAM in the rear and look for a front diff assembly with the 3.42s already in place. Anyone foresee any concerns swapping in a used assembly? Anyone have any leads on some used diffs? Thank You

From what I have been able to find so far, original parking sensor and fog harness PN was 23187813 which superceeded to 84307173. This is turn *should* be plug and play into the OE harness (Seemingly). Then you would need to buy an OE headlamp switch which has the fog function, verify the wiring from the switch to the BCM. You would need to find someone who had the ability to change the function list in the BCM to "open" or allow the fog lamp function. That would make it as OE as it gets... The videos above are a much cheaper and quicker alternative.

ask em to put in a new trans t-stat while its there. 21-NA-199

Can you elaborate more on "high fuel pump is leaking fuel into the engine". Into the engine compartment? If your having wet crowns its likely the injectors are bleeding as that's the last fuel component going into the cylinder. FYI for a high pressure pump recall https://www.google.com/url?sa=t&source=web&rct=j&url=https://static.nhtsa.gov/odi/tsbs/2015/SB-10057680-1621.pdf&ved=2ahUKEwjQhtHYpZH0AhWUbs0KHbWrDPQQFnoECAsQAQ&usg=AOvVaw1qP5RhS1ZZnpgcP3CQCVWd

In my experience, if you go in with knowledge, some information and background and escalate your concern- they usually work with you. I was offered they cover something out of warranty 50%. So while he might not get it for free, walking in and acknowledging GM has a known problem with the gearbox - they may be willing to work with you. Never hurts to try, worst they can say is no which leaves you in the same spot as you started.

21-NA-199 The TSB states that a new T-stat is being used on the 6-speeds, down to 158F from 194F. So for all those who did the pill flip - you beat GM to the punch. https://gm-techlink.com/?p=15389

Its low mileage but do you have any oil consumption? Plugs look OK? Compression good? Id try a can of seafoam through the intake to clear up the valvetrain. I wonder if there isn't some coking on the valves, carbon dropping into the cycling causing pre-ignition.

FYI there is a GM TSB out for a new gearbox t-stat unit. instead of being fully open 194, its now fully open 158 21-NA-199

go to the dealer, state 21-NA-199 and demand GM cover the gearbox - IMO

Plenty of discussions with the dealer and techline in regards to the operating temps that GM set forth on the powertrain for our Tahoe. They said both engine and gearbox temps were normal and as expected... I ended up doing a Katech 174 and trans thermo pill-flip about a year ago and have been much more happy ever since. And now this is released for the gearbox... https://gm-techlink.com/?p=15389 Little bit of irony.

I live in AZ, morning drives to work place me in the 30s and I'm seeing low/mid 180s. With amb temps warmer in the afternoon, seeing low/mid 190s. I think where the most benefit will come is during the AZ summer. I noticed that when I cycle the HVAC on (engage compressor) the grill shutters started to open when at speeds above 30mph. Meaning, in the summer the compressor loads going to be high and I expect my shutters to be controlled open majority or the time. If this turns out to not be the case, that's when I'll work on tricking the vane motor. Otherwise, dont really see much need for the effort yet.

Was talking with Lew and Diablew tuning about the shutters, there is no access to this within the ECM. Even with my 174, I still see ECT in the 190s consistently due to a lack of airflow across the radiator. From what I gather (AC compressor OFF), the shutters will open when slowing / almost stopped. Remain open when stopped and at speeds up to high 20s and then close at about 30mph and stay closed thereafter. I'll probably just trick the grill shutter motor and remove the vanes.

disregard cant delete comments anymore?

http://blackbearperformance.com/IntakeTestResults_2016.asp

You need to keep the motor plugged in and rig it to still make the swing, no way around it.

Can you please elaborate? AZ summer heat easily reaches 120F (even hotter at times). Engine heat, soaking, heavy loads, hot air removing heat from hot coolant, ect - this all equates to heat. Hot engine, hot intake temps, just heat in general. Let's not forget the L83 runs on the hot side as it is (210F nominal with a fully open t-stat at 232F). FI generates heat. So how would/could going one heat range down not be beneficial? FI applications utilize colder plugs. Hotter plug, retains heat, high cylinder temps, higher probabilty of pre-ignition and pulled timing. In any case, I installed a setup colder on the L83 and we shall see how she runs over time. I'd still be genuinely curious your thoughts and happy to chit chat via DM if that happens to be easier! Thanks

Did you install the same plugs in? Been thinking of going to a heat range 6 vs the OE 5 (being that I live in AZ).

@Larry Cooke any update?