E85 conversion?

[swathdiver]

The LC9 uses the larger injectors because E85 is less powerful than regular gasoline but does burn cooler allowing the engine, when it detects E85, to alter its parameters to make more power. GM has posted the dyno results for the LC9 and other Flex Fuel engines.

If the E85 is priced right, one can save money by running it compared with regular gasoline. It's a simple function of math to see if it would work for you depending on your locale (gas prices) and the mileage you experience with your truck. These trucks run like crap on 87, I get better mileage, so much better, that it costs less or within 1 penny to run 93 octane compared with 87.

 

[S33k3r]

The LC9 uses the larger injectors because E85 is less powerful than regular gasoline but does burn cooler allowing the engine, when it detects E85, to alter its parameters to make more power. GM has posted the dyno results for the LC9 and other Flex Fuel engines.

If the E85 is priced right, one can save money by running it compared with regular gasoline. It's a simple function of math to see if it would work for you depending on your locale (gas prices) and the mileage you experience with your truck. These trucks run like crap on 87, I get better mileage, so much better, that it costs less or within 1 penny to run 93 octane compared with 87.

Do you have a tune, or is the running better with 93 stock? I'm thinking of trying it myself.

 

[swathdiver]

Yes, I just recently had the truck tuned by Black Bear. But right now it's got a bad cat, and is probably why the mileage has been so poor since I bought it.

When the alcohol content was 23%, the truck averaged 15.4 mpg and with 58% it averaged 10.8 mpg. Next tank is 93, and it's struggling to maintain 12, but we idle a lot and that cat has gotten bad enough to throw a P0430 code.

 

[Marinezuniga]

So here we are in 2022 and gas in California is 4.80 plus per gallon. I've been doing research all over and would like to know if all I need is the larger injectors to run WITH on my 2001 Yukon with the 5.3 gas engine. E85 is $3 per gallon

 

[SnowDrifter]

So here we are in 2022 and gas in California is 4.80 plus per gallon. I've been doing research all over and would like to know if all I need is the larger injectors to run WITH on my 2001 Yukon with the 5.3 gas engine. E85 is $3 per gallon

Pulling on old brain cells here

but IIRC, at a base level, larger injectors + tune should do it. I wonder if the tune is even needed. Theoretically, ECM should compensate and remap fuel with the O2 sensors, though you might get a CEL complaining about fuel trims.

Little difficult on an '01 since it was never offered in the flex-fuel variant, so I wouldn't expect any of the wiring harness/ECM functionality to be there.


What I don't know, is if there were any changes to the fuel pump. Like, stainless steel parts or lubrication design differences.


Keep me posted on what you find? I'm a touch curious on how this goes

 

[Mudsport96]

Ok so below are some parts you will need for converting an 01 to flex. The fuel pump and fuel regulator are from an 02 since that was the first year for a flex fuel Tahoe. You will need flex injectors and a flex fuel specific fuel rail. I didnt search that because i would go to a wrecking yard and find a matching set from a wrecked vehicle.
The sensor in the picture is from a 2012 or 13 impala. It will work like tahoe one, just cheaper and more compact. You will have to find the correct plug and have it wired into the ecm harness.
Now... your best bet for ecm is to take one from a wrecked tahoe that was originally flex. It will have the correct calibration for fuel, timing yada yada. You would just need to have the anti theft programmed out of it. And for California probably have the VIN changed to match your vehicle to pass inspection.
Otherwise you will have to take it to a tuning shop and they would have to do a flex tune and i would be willing to bet an 01 ecm doesn't have to hardware to even be converted to flex since it wasnt an option till the next year.

 

[Fless]

The FF pumps run at a few lbs lower pressure, but provide more volume.