Putting A Chip In A TBI Truck

[woody80z28]

Check out gearhead-efi.com for info on tuning with the stock computer. I see no need to swap to EBL.

 

[454SSguy]

Lean cruise with stock ECM?

 

[woody80z28]

Lean cruise with stock ECM?

Yup. It's call "highway mode" but it does the same thing. I haven't enabled it on mine yet since I'm still playing with the VE & AE...but I plan on it. I am running lean cruise on my Beretta with the stock ECM. 32mpg!

 

[454SSguy]

Good to know. Had not heard of that. I know that my 04 GTO had it but was not enabled due to EPA Regs. The 05-06 GTO do not have it available at all.

 

[1badcj8]

OK... I'm trying to keep up with what you guys are saying but it seems like Chinese arithmetic to me. Any chance one or both of you can break down these last two or three posts for me? I don't get the "lean cruise" and how it translates to "highway mode". Does highway mode hinder or cut back on performance.

And by the way... The more you guys banter back and forth the more I learn, please continue!

 

[454SSguy]

Lean cruise or "Highway mode" as it's called on stock ECM's (I didn't know that) does this in a nutshell

When your car hits a certain set of parameters usually....
These #'s are just for example you can make them whatever you want.

55+mph
for more than 60 sec
with 15% or less throttle

Then it activates, causing the truck to "lean" out. Means it gives it less fuel, which actually makes more power but is dangerous at WOT or higher rpms. Get 2-3 more mpg's on the highway. That's how it was explained to me anyway. Someone feel free to jump in if I missed anything or was told wrong.

It is not standard on US cars b/c the leaner conditions raise the emissions so the EPA has banned it. If you ask me the oil companyies have the EPA in there pocket as they also determine if a major car company (GM, Ford, ect) are allowed to mass produce a car or not. Might be why we don't have any of those 50+mpg cars here in the states like overseas?

 

[Chris]

Lean cruise or "Highway mode" as it's called on stock ECM's (I didn't know that) does this in a nutshell

When your car hits a certain set of parameters usually....
These #'s are just for example you can make them whatever you want.

55+mph
for more than 60 sec
with 15% or less throttle

Then it activates, causing the truck to "lean" out. Means it gives it less fuel, which actually makes more power but is dangerous at WOT or higher rpms. Get 2-3 more mpg's on the highway. That's how it was explained to me anyway. Someone feel free to jump in if I missed anything or was told wrong.

It is not standard on US cars b/c the leaner conditions raise the emissions so the EPA has banned it. If you ask me the oil companyies have the EPA in there pocket as they also determine if a major car company (GM, Ford, ect) are allowed to mass produce a car or not. Might be why we don't have any of those 50+mpg cars here in the states like overseas?

We're all still learning about how highway mode works with the stock ECM. The code is there to start with, but due to EPA regulations (not so much emissions as this mode is a quasi-open loop state where the ECM is commanding a specific stoich instead of calculating fueling requirements via stored algorithms and not providing 100% feedback) it's not turned on. Older systems are simply "patched" but it still needs to be activated. I've had my boat anchor of a 5.7L returning a solid 21-23.5mpg consistently (500 miles to a tank is normal now) for a couple of years now, even with E10 fuel. Of course your mileage may vary depending on topography and vehicle weight. I spend 60-70K miles a year on the road at 65mph for hours on end so that's why my numbers are so consistent. I've pushed it about as far as I feel comfortable doing with the TBI system though. Fueling is pretty dead on with my wideband when I have the tune set to command 16.2:1 AFR at high MAP, and it feeds down to around 15.2:1 based on engine load with varying degrees of SA added (because leaner mixtures burn slower), and ONLY once all parameters are met for lean cruise operation. Also remember it doesn't go into LC and stay there, it will cycle off and on to prevent the catalytic converter from being damaged.

That's a quick overview but there's a ton more info available. Different engines will react differently so YMMV.

 

[cat-chevymech]

Lean cruse highway mode ? How do i activate it in my 94 federal emissions truck i have a gutted cat so i dont wory about a cat just engine relibility as this is my dd towrig and work truck with the ocasional wheelin adventure
I am currently only getin 15 to 16 mpg but im looking for 18 to 20 at least what do yall recomend i have a tbi spacer gutted cat and cai would a 6pack chip help me get to this point ? If not what should i do any help would be greatly appreciated im great with diesels but im still trying to learn these tbi trucks so any help would be greatly appreciated thank you and have a great day

 

[shaggy08xr]

Wow, theres is some really good info here.

 

[Gatorboy]

Is it worth the $?