Filled up my sisters E85 Yukon ...now runs like crap.

[iamdub]

Hence me asking for the L code.

Yup. The truth goes a long way towards helping diagnose such issues.

 

[thompsoj22]

WTF? So many different choices out there, Here in the "held hostage by democrats" state of CA they use a technique called "extortion". You know exactly what fuel you are putting in because you are taking food off the table with every gallon you pump. My last chevron fill up with premium at $4.78 per gallon was $126. You are extreemly focused everytime you pull into a gas station, you stare at the pump in disbelief, you are never relaxed enough to make an error by grabbing the wrong handle! LOL. I know I know no politics, but it is soooooo ugly out here! Welcome to CALI, you can take a dump on the sidewalk and stick a needle in your arm in public, But let the meter run out on your parking space and it is a $75 citation, fail to pay, $335 fail to appear warrant issued for your arrest. Now for the original post, find a way to siphon as much as possible out of the tank, my opinion is to than add just five gallons premium and drive it at freeway speed until low level fuel light comes on than drive it another 25 miles and fill it with premium.

 

[OR VietVet]

Yea, and the idiots that started all this crap in Ca. have now sent people north to Oregon and Washington to screw us all up. Thanks. LOL!

 

[gat0r]

always good to look at label & not the color of handle. (as well as know the vehicle you are in)

i was traveling last year & noticed a station had yellow handles for diesel.
where all other stations i have seen are green.

stopped some guy from filling up diesel in his hybrid car. lol

 

[swathdiver]

Yeah, with "gas" cans, red is for gasoline, yellow for diesel, blue for kerosene and then next week it will all change!

 

[bondservant2]

Thanks to those who posted. My wife and I were out on a date so couldn’t respond. I have to clarify that I have never OWNED an E85 capabale vehicle and have zero experience with them. My confusion is because I was told it’s E85 , it has the yellow filler cap stating E85 but no flex-fuel emblems on it. A quick internet search and a GM website came up stating E85 but not flex. Again I have no experience with flex-fuel vehicles.

So I learned that ALL E85 vehicles are flex-fuel (yes..?) and should run fine on even “regular” unleaded. So I have to guess more than likely bad fuel. Although I have to agree the problem should have surfaced before 30-miles of travel. So I’m still confused and still wondering if I should just add good gas and run it....

I’ll check the codes on it when I am able.....it’s not at my house.

 

[HiHoeSilver]

Thanks to those who posted. My wife and I were out on a date so couldn’t respond. I have to clarify that I have never OWNED an E85 capabale vehicle and have zero experience with them. My confusion is because I was told it’s E85 , it has the yellow filler cap stating E85 but no flex-fuel emblems on it. A quick internet search and a GM website came up stating E85 but not flex. Again I have no experience with flex-fuel vehicles.

So I learned that ALL E85 vehicles are flex-fuel (yes..?) and should run fine on even “regular” unleaded. So I have to guess more than likely bad fuel. Although I have to agree the problem should have surfaced before 30-miles of travel. So I’m still confused and still wondering if I should just add good gas and run it....

I’ll check the codes on it when I am able.....it’s not at my house.

Yes. Flex fuel simply means that the vehicle is capable of running on fuels that contain up to 85% ethanol (E85). They will also run on E30, E15, and regular unleaded (<10% ethanol) of any octane rating.

The L code from the glove box will simply verify that the vehicle does, in fact, have a flex fuel engine. Given your yellow cap, we'll assume yes at this point. Good thing.

Different model years use different means of determining the alcohol % of the fuel. Some have an actual sensor, some use a virtual one based on other data. They can certainly fail or get confused. A scan tool can be used to reset it, but this should not be performed with ethanol in the tank.

 

[bondservant2]

Took it to the Dealership that is open on Sunday and the diagnosis :

RPO code L29. Fuel filler cap is yellow marked E85.

Fuel in the tank tests at 75% alcohol. So the blue handle pump is E85 at this station. Which I did verify twice. The Mechanic was able to run it on fuel independent from fuel in the tank and the problem continued, so that rules out bad fuel - or so it seems.

There is a misfire on the #6 cylinder with a history of misfire on #4. Spark plugs and wires check good on both.

So the good news is that I didn’t cause it. It was coincidental to me fueling it. Bad news is that it’s still happening and possible an internal engine problem . Maybe a stuck lifter or related to the fuel rail / injectors.

It just sucks that it happened while I was driving. I feel somehow responsible.

 

[Fless]

The fuel door should also have a small sticker that tells if it's E85 compatible. The RPO code L29 -- that doesn't seem to be a good code. Could it have been L59?

 

[OR VietVet]

Mine says L59 as well and I know my engine is a flex fuel.