Dumb question for FFV owners

Has anyone with the hard start FFV issue just tried running E85 in it? My BIL has a 2016 FFV 5.7 with the codes and issues and can’t get a new fuel pump (which I’m not sure he needs) or resolution of the elevated ALC% detected by the ECU. If the computer thinks the ALC% content is 80 something, wouldn't it run fine on E85?

 

I remember reading this a while back and thinking it would be helpful for FFV owners. Don’t have an answer to your question but this is worth a read. https://www.tundras.com/threads/res...-bidirectional-scan-tool.123799/#post-3171202

 

Yup, that is one of the options we’ve looked at

 

FFVs can have issues. Seems safest not to ever use E85.

 

The question is if the computer thinks the alcohol content is 80% or more, has anyone used E85 when that’s the case and the truck has run normal. It will not run normal on pump gas with an “E85 tune” from the computer. But has anyone used E85 on their FFV 5.7 when the truck is registering a false alcohol content of 80% or more. And how did the truck respond?

 

I have wondered the same thing... I don't have a FFV so no need to know, just curious as well.

 

I don’t have experience and would never try this - just here to remind people the maintenance schedule calls for 2,500 mile OCI if you use E85 since it’ll dump so much ethanol into the oil.

I’ve had to reset the ethanol level using Techstream and that’s what I’d suggest.

 

Does anyone know what sensor detects or measures what type fuel is used?

 

There is no sensor. When a refueling triggers the alcohol learn it's keeping track of how much fuel it has to add to maintain stoich burn. If injectors are plugged, if the fuel pump is underperforming, maybe even if there's a leak in the exhaust header drawing air in before the a/f sensor... Any of that will show too lean and the computer will set a high alc percentage.

Ironically running e85 now and again will clean any varnish out of the pump and injectors and blast any soot buildup off the a/f sensors. I could see it might prevent the problem for some trucks. If you're worried about the oil thing, you run a tank or two then switch back to gas right before the next oil change.

However if the issue is already happening from low fuel pressure etc then you don't want it running lean on the alcohol, so don't romp on it if that's the case

 

FWIW my truck has the opposite problem if the number on the scangauge is correct. The alc% never quite rises up to the actual amount as if it always gets more fuel than expected. The highest I've seen it read is 60% and that was after several consecutive ethanol fillups. Then I filled up with 15 gallons of regular 87 octane e10 and it immediately dropped to 5%. Then 12 gal of ethanol, now shows 32%. If only we could have a real sensor.

 

Man I hate seeing these FFV hard start threads.
Makes me want to sell mine immediately so I can stop waiting for the other shoe to drop.

 

My 2014 had a very mild case of hard start and it was cured by a re-flash/update at the dealership. My 2016 doesn't have it at all.

 

Mine just started doing this after my local station switched to summer blend. I’ve run 89 for a few tanks and it seems to have helped.

 

I have a 2015 FFV with 120k+ miles on it. Owned it for 2 years and put about 25k miles on it. I've never had a problem.

I never ever use E85 (I think I'd rather run out of gas than use it!), and it's highly unlikely I'll ever use it below 32 degrees ambient temp. I also use premium gas most of the time, or mid-grade minimum.

EDIT: I'm not sure the above info is relevant. Just sharing my practices.