Shifting Issues:Result Of Ethanol In Fuel?

[Carey Frennier]

I went 245 miles (one tank in the city) with my Xcal3 87 perf tune with no transmission shifting issues at all. I bought the gas at Stewarts. on 10/4/08



I just filled up last night 10/30/08 with 87 Octane from Sunoco. I had the same Xcal3 87 perf tune installed. Imidiately I started having transmission trouble. The worst I've ever had. It was like riding a bull or rolling down a hill on a log!



I drove back to the gas station to read the pump to see if I bought the wrong fuel or something. It said that all fuel contains up to 10% Ethanol.



I then drove to Stewarts to read their pump. They didn't have anything that said there was or was not, ethanol in their fuel and, of course, the employees there had no clue.



I wonder if this could cause an issue with the shifting.

 

[TrainTrac]

Honestly, I don't think so. If I'm not mistaken, 10% ethanol in gas has been federally mandated for about three years now, so even if the station doesn't have a sticker on their pump, it's probable that it still contains 10% ethanol.



The alleged reason for this was that it was a "more green" alternative to some other additive that was supposedly more harmful to the environment. Personally, I think that it was pushed by the farm lobbyists in order to force more of their product into the market, since it already couldn't survive without taxpayer subsidies.

 

[Michael Cacioppo]

A 10% ethanol mixture vs straight gasoline will should not cause your problem. I've notice that once in a blue moon the ECU has a nervous breakdown and makes the Trac run poorly. Shut off the key and restart makes the problem disappear. It has happened to me twice in 30K miles.

 

[gary s]

i think the good ole tranny demon got ya :angry:

 

[Doctor CAD]

My 03 gets about 20% less mpg's on 10% ethanol vs. 0% ethanol. My 03 and 01 Tribs also did way worse on 10%.



Newer ECUs can compinsate better, my wifes 06 G6 doesn't even notice a difference.

 

[Richard L]

Ethanol in gas is not Federally mandated, but it is in some states and manicipalities. It is also used more commonly in Winter fuel blends in some parts of the country since alcohol will mix with water and prevents fuel line freezing.



Ethanol is also a very inexpendive way to raise the octane level of the gasoline and you will get better mileage if the fuel does NOT contain any ethanol.



In the end, I doubt that the ethanol caused your transmission problems. It was either just a coincidence or as previously stated, your ECU just booted up bad and had a brain fart. It's a know issue that on very rare occasions, Sport Tracs will start and run very rough and act really goofy. Usually just turning the engine off and restarting it will cure the problem. These incidents rarely happem more than about once per year, and are impossible to duplicate at the dealership for service.



Several years ago, someone here had a theory that I kind of agree with. If you flip your key on and start the engine really fast, perhaps the computer did not complete all of it's internal diagnostices and not everything was setup for a clean start. If you turn the key on, and then pause for about 1 second before you start the engine, it will give the ECU time to properly boot up and run all if it's diagnostics and insure that all the software has loaded before the engine is cranked up.



Other than that, it's probably nothing to worry about unless your truck continues to run poorly. Then you may have other issues, but it would not be just the ethanol...Perhaps they had too much water in their fuel, and you just got a load of bad gas>



...Rich