E85 Problem

[jfreeballer]

I have a 1999 Ranger with the 3.0L Flex Fuel. I've driven it about 120,000 miles on 87 octane gas, but recently a station opened up by my house that offered E85. I figured what the hell, it's $1 per gallon cheaper, so I filled 'er up with E85. Problem is, immediately after it caused my check engine light to turn on, and the code came back saying my engine was running too lean. If I have a flex fuel vehicle, why would it cause this problem? A friend of mine told me it isn't smart to go with a full tank of E85 after running gasoline for so long, but rather to combine the two like half-and-half. But my owners manual says that my engine is compatible with gasoline, ethanol, or any combination of the two...and isn't ethanol already part gasoline?? Any help would be appreciated!

PS. The code cleared after I filled it back up with 87 gas.

 

[Bob Ayers]

It sounds like your E85 sensor is not working properly. E85 requires more fuel, so the PCM should increase the injector pulse width when running E85. If the E85 sensor is not telling the PCM that your running E85, to increase the injector pulse width, you will have a lean condition.

 

[jfreeballer]

Is this something worth fixing compared to the dollar or so per gallon I can save on using ethanol rather than gasoline?

 

[triumphrider-1]

Its up to you if you want to fix it; but for myself, I would fix mine.

When you run different blends of ethanol your fuel economy changes also. With E85 you can expect a loss in fuel economy somewhere in the range of 10%-30%. So for that percentage loss the fuel will need to also be that much cheaper.

 

[jfreeballer]

So if ethanol decreases fuel economy, why use it? Besides the cost.

 

[triumphrider-1]

You produce fewer emissions with it and have a potential for more hp with it.

 

[dorman68]

Sounds like a bad flex fuel sensor.

 

[Froggmann]

I believe there was a TSB on this. IIRC run a couple tanks of E85 through and the CEL will go away.

 

[oldfordman]

If the E85 sensor is bad, it should be showing a code. It has to be working properly to pass emissions inspection if required where you live. If your PCM did not adjust for the E85, the engine would have been running bad and pinging like crazy. Hope it's not the sensor, the dang things are expensive! If it runs well on the E85, I agree with Froggmann- run a few tanks and see if it clears up. The E85 will clean a lot of crap from the system. In PA, i can't find the stuff, so it doesn't matter. However, I agree with the statements about lower fuel mileage- I see a repeatable 1-1.5 mpg drop with the 10% E that most stations are pushing today, in all 5 of my vehicles, going back many years. (yeah, I'm anal, and document my gas fillups, miles, gallons, type of gas, etc)

 

[Bob Ayers]

If the E85 sensor is bad, it should be showing a code.

It is, re-read the OP, a lean code would be thrown if the E85 sensor was bad, and not detecting E85 was being used. It wouldn't ping, because the
timing table advances the timing with E85, and E85 is a higher octane.

 

[oldfordman]

Bob- My understanding is that the fuel sensor sends out a continuous signal to the ECM, varying the frequency or wave width (I forget which) depending on the % alcohol in the fuel. The ECM then uses that to adjust the timing and also the injector pulse width to supply more fuel with E85. If the sensor was bad, wouldn't that throw a code before he put in the E85? If the injectors were dirty, or slightly low fuel pressure, could he be OK with gasoline, but not able to flow enough with the E85? Not arguing, you are the expert here- I just want to understand because I have the same vehicle ( 99 flex fuel )

 

[garo24]

Any follow-up on this.. I have the same issue!!

I have a 2000 3.0 Ford Ranger XLT Flex fuel and the same thing is happening to me. Last year, I decided to run some E85 in it and when I did, the CEL came on. Took it to Advance Auto and got codes PO171 and PO174, lean on banks 1 and 2. Reset codes, came back within 25 miles or so. Thinking there might be water in the tank, filled up with 87 octane instead, ran some STP gas treatment and cleared codes. CEL nor codes came back.

Fast forward to now.. so I decided again to run E85 in my 2000 flex fuel ranger and within 20 miles, the CEL came on. Figured it would since I was running E85. Stopped on Advance Auto today to get codes, same ones... PO171 and PO174, lean on banks 1 and 2.

So... why do I only get those codes when I run E85 and not when I run regular 87 octane gas?? I have changed the passenger side O2 sensor and O2 sensor after the cat.

Someone mentioned a TSB on this? Is it the flex fuel sensor? That part is way to expensive to just buy, replace, and hope.

Any ASE or FORD experts out there experience this before?


Also, when it happened the first time, I took it to my mechanic thinking that it was a vacuum leak, mechanic said no leaks, fuel pressure was good and PCV valved was good.
Thanks,
Garo24

 

[triumphrider-1]

Go here to get the basic TSBs.
http://www.ford-trucks.com/tsb/tsb.php/m-FORD

You'll have to go to a dealer or maybe someone on here can help you out with the full text versions.


There is a way to test the sensor (it was mentioned in a thread on here), but where specfically escapes me. Try searching the forum for flex fuel sensor stuff.

How low on gas were you before you filled up on E85?

 

[garo24]

I was on empty when I filled up with E85. I would say I put in 16 gallons of E85 on a 20 gallon tank.

I filled up again today with E85, 15 gallons. Codes were cleared by Advance Auto, CEL came back on, on my way home from work. In both instances, I have purchased the E85 from the same station. Once was last summer when it was warm, and this week. It stated that it was at least E70.

Garo24

 

[triumphrider-1]

If you run it again, make a roughly 50/50 mix of E85 and gasoline. It also may not hurt to check the flex fuel sensor.

Yeah, the winter blend of E85 is E70, so from fall to spring it'll be E70. When they switch it from one to the other I don't know though.