Thread: Running e85 on stock fuel system

I read up that it can be done on the stock fuel system and that you just have to swap out the injector o rings with 95 Taurus rings. Obviously a tune would be a must to get the full benefit. Just wondering if this is true and if this is the set that would have to be purchased.

http://shop.advanceautoparts.com/p/f...chTerm=o+rings

No. No. No. and did I say no?


E85 requires AT LEAST 42.5# injectors, recommended 60# or 80# depending on power levels. You need a tune and anything below a 3.2/3.0 will require a 200+ (Recommend 300+) lph fuel pump. You also NEED a tune. The car will not run without it on full e85. You can get away with e10 maybe e15, but anything more your trims are going to be so whacked your car wont know what to do. I have been running the stuff for over a year now. Love it, but you need the proper stuff.

EDIT: I got o-rings from the part store, fel-pro ones... they work fine.

Originally Posted by darkhorizon

You can swap 42lb injectors in with the e85 swap and it runs great no tuning.

I imagine you will struggle with fuel pumps and filters making sure that you dont drop fuel pressure.

With 33lb stock injectors you can run about e60 on a stock pulley. You will see a very small mileage drop. Its a great money saver and you can mix with 87 octane.
http://www.grandprixforums.net/threa...e-in-E85-areas

All injectors are not the same you don't just plop in bigger injectors without proper data, what about your transients?

I would still recommend tuning. Something about running a completely different fuel on a non-tuned pcm worries me.

The early flex fuel vehicles didn't have accurate ethanol sensors. The factory tunes also don't optimize e85,like it could be.

If you tune the vehicle with extra timing and take the time to see the actual stoich of the E80-E89,you're getting. You will gain some.

Originally Posted by K Kraziee

I read up that it can be done on the stock fuel system

ummmmmmm, ok!
Mind if you were to post such references so we may examine it too?

that you just have to swap out the injector o rings with 95 Taurus rings.

Ummmmmm, nope!

Obviously a tune would be a must to get the full benefit. Just wondering if this is true and if this is the set that would have to be purchased.

http://shop.advanceautoparts.com/p/f...chTerm=o+rings

Not just to tune to get full benefit... But make it work.

but really, why not just give it a go and let us know how it all worked out?

To 'my' knowledge, you'd need to:

1. upgrade fuel pump wiring at a minimum, or bigger pump
2. Larger injectors
3. Larger, finer fuel filter
4. Tune to adjust increased fuel consumption and afr change due to different fuel used.

Good Luck & Have Fun out there!

In theory going E85 with injectors that are 30% bigger could work on a stock tune. I havent tried it but I have a friend that is experimenting with the idea on his DSM. To see any benefits you would also have to give it more timing or more boost.

Other than tune and injectors though, I ran my stock pump, lines and wiring down to a 2.7" pulley on E85 before it started leaning out! My 302whp dyno was with the stock pump starting to run out of fuel after 5k rpm. Stock replacement fuel filter and stock replacement O rings no issues in 20k miles too btw

There's really no need to guess. I mean its really easy to find your exact stoich with a small beaker. 10ml of water AMD the rest gas/e85 shake it up watch it settle bam. Poor mans ethanol testor

Isn't the tune as simple as adjusting the stoich. reference in the cruise tables, and then changing the PE target AFRs as well for the E85?? Wondering if I could pick up injectors, a stock pump rewire, and tweak as few as 2 or 3 tables in my tune and run full E85 without any issues.

Originally Posted by 97AutoXVette

Isn't the tune as simple as adjusting the stoich. reference in the cruise tables, and then changing the PE target AFRs as well for the E85?? Wondering if I could pick up injectors, a stock pump rewire, and tweak as few as 2 or 3 tables in my tune and run full E85 without any issues.

You completely can. I picked up a set of 60's used cheap, bolted them in. No need to change any target AFR's, Stoich for all fuels = Lambda 1 it doesnt matter if its E85 or gasoline the O2 sensor doesnt know the difference. For instance running E85 with a wideband setup for gasoline, when it is showing 14.7 you are actually at E85 stoich of 9.76 or lambda 1 all the way around. The gauge is just converting lambda 1 from the sensor to AFR so you have something relatable to read on the gauge. Your stock narrowband works the same way. AFR is just a way to read stoich for different fuels.

Either way all I needed to do is change the injector tables from stock to 60's then the 30% for e85. Ran the tank dry with the pump on and a fuel line off then filled with E85. Fired right up with no other changes, no pump, no rewire, no injector o-rings, not even a filter change, only took 20 minutes. After that I set the timing from stock to 22* and dropped from my 3.4" pulley to my 3.1" picked up probably 30 hp.

Originally Posted by Anthony Smith

You completely can. I picked up a set of 60's used cheap, bolted them in. No need to change any target AFR's, Stoich for all fuels = Lambda 1 it doesnt matter if its E85 or gasoline the O2 sensor doesnt know the difference. For instance running E85 with a wideband setup for gasoline, when it is showing 14.7 you are actually at E85 stoich of 9.76 or lambda 1 all the way around. The gauge is just converting lambda 1 from the sensor to AFR so you have something relatable to read on the gauge. Your stock narrowband works the same way. AFR is just a way to read stoich for different fuels.

Either way all I needed to do is change the injector tables from stock to 60's then the 30% for e85. Ran the tank dry with the pump on and a fuel line off then filled with E85. Fired right up with no other changes, no pump, no rewire, no injector o-rings, not even a filter change, only took 20 minutes. After that I set the timing from stock to 22* and dropped from my 3.4" pulley to my 3.1" picked up probably 30 hp.

Excellent info and detail. Thanks!! Where exactly is the injector table?? Maybe I just have to jump back into the tune this evening and take a look. I also understand what you're saying about the wideband and AFRs, Lambda = 1, etc. That makes sense.. Does the computer always target lambda = 1, and then target a percentage of lambda based on what the PE table/mode is targeting? (when you are on the throttle enough to enter PE mode).

I'm thinking with the different results, I could safely run a 20/80 mix on stock injectors for now until I upgrade to bigger injectors then run more. I wouldn't run full e85 unless I was tuned and had a different fuel system. It just seems like with the mixed results it should be Ok. Is it worth it, idk. But e85 here in Milwaukee is like 2.99 so it's a lot cheaper than 93 at the moment.

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In addition, the computer targeting lambda = 1 would help validate why DarkHorizon was able to get away with just switching to E85 and 42.5 lb injectors and not changing the tune at all and still running okay... right?

Originally Posted by 97AutoXVette

In addition, the computer targeting lambda = 1 would help validate why DarkHorizon was able to get away with just switching to E85 and 42.5 lb injectors and not changing the tune at all and still running okay... right?

By running okay is a very relative word.. What I dean OK might be ****ty to you.

Trust that you'll want the injector data input into the PCM. You'll want proper driveability transients etc...

Originally Posted by 91parkave

By running okay is a very relative word.. What I dean OK might be ****ty to you.

Trust that you'll want the injector data input into the PCM. You'll want proper driveability transients etc...

Yepp, I would swap the injector data and compensate for 30% addition needed for E85 at a minimum probably. Guess from there I would just do a lot of scanning and monitoring to find out what I'd need to change/tune along the way.