e85

[Upshift]

Originally Posted by Panacea

Oh who shoved the corn husk up your ass?

Deleted for the common good of the community.

[cardude007617]

isnt this against the gagt forum guidelines? ^^

[Upshift]

there all better

[silverbullet51]

I'd love to see how this guy's experiment turns out, sometimes the best learning method is by doing. Even if it's done the hard way and the car ends up at the salvage yard. This thread has been quite informative and entertaining.

On a side note: if anybody decides to put diesel instead of gas in their tank and debate on that, then I'll have some words of my own...

[PhantomLover007]

I thought this was closed or locked??

[peppermill]

So a week ago I got a tank of fuel that ended up being "better than E90" to quote the guy that mixed the fuel at the co-op. He said he misjudged how little E75 was in the tank when he added 100% ethanol to it. I had to immediately drive 280 miles on it, for a business meeting. And within 5 minutes of fueling up got a strange new noise from my engine compartment. Sounded like mild knock, all the time.... or an exhaust leak. Incredibly faint. It was the first time during the process that was worried that I had actually screwed something up for real.

Other than the sound, the trip was uneventful.

The results were: 24MPG. on "better than E90" So yeah, with that kind of mileage, I'm pretty sure it was leaning out.

So after that, I went to normal pump gas. Sound stayed. Another tank of normal pump gas. Sound stayed... and now it's missing a little. Enough to feel it. And then a little more. Then ubber-gage showed up. Just in time! It was showing misfires on #1, and a few on #5.


Now... before I started this process, the car was ready to turn over 100,000 miles, and I took it to the shop that my friend and trusted mechanic used to run, he had just sold out to another guy. I asked for plugs and wires, (was getting some tick in the stereo, and besides... it was "just time"). He called and said it was leaking coolant.. the dreaded intake gasket leak, so I told him to go ahead and fix it (big mistake!!) After plugs and wires, the very next tank of gas was a blend of E40 and I started the experiments.

So now that I'm hearing this mystery sound I decided to check all the plugs, to make sure that they were in tight. I pulled them to inspect them too, and they all looked brand new. I looked up the AC Delco part number and the part number the magazine showed was different from the plugs that were in the car. So I decided to replace them all with cheap copper core champion plugs, just so they were all the same. Turns out that after they were all out, I noticed that there were TWO different types of plugs in the car! (neither of them were apparently the right ones) I suspected the guy was a tool, but what I found later was a little more shocking. See, he also did the intake gasket. So now that I'm suspicious of him, I started inspecting things. I found that every hose clamp on the intake was loose. ALL OF THEM. The mass airflow sensor was rotating freely... and had crud on the screen that I had to blow off with compressed air. He just never tightened the hose clamps down. So now I have this overwhelming desire to punch my former mechanic in the face with the wrong spark plugs, and wrap a large hose clamp around his neck and show him how to tighten down a hose clamp properly.

I took it to a mechanic because I wanted to spend a weekend with my family, rather than wrenching on the car. As it turns out, I paid money so I could eventually end up spending a weekend wrenching on my car anyway. Lesson learned.

So I'm now back to stock (including fuel) and everything seems to be running tip top. No misfires. No exhaust leak/knock sounds. All is well. Scan gage is hooked up, and things seem to be at normal levels of performance.

I'm going to start this process of pouring in smaller and then larger and larger concentrations E85 all over again, and see what I get for numbers.

Just from what little scan numbers I have (and a little math) I have a sneaking suspicion that even running E40 may cause a lean condition at full RPMS at WOT, despite the check engine light not being lit, and that one may very well be able to run E85 as long as the throttle and RPMs are kept low and slow.... with incredible leaning at WOT and full RPMs under E85.

When I get numbers, I'll post them.

[peppermill]

Originally Posted by Shock24Z

I don't know about all that ... I just go by this:

http://www.ecanfix.com/~mdhamilton/dutycycle1.html


I generally don't like to see 20ms or higher while scanning and above 80% duty cycle isn't good.

I also wouldn't use IPW's to determine whether you need bigger injectors or not without a proper tune on the car. The PCM is still commanding the stock AFR's, not the ones you'll be running. So even if your IPW's look good now they could go static later after tuning.



Any A/F you scan for without a wideband will be a commanded A/F. Not calculated.
Past 70%(IIRC on a stock 3400) you will enter power enrichment (PE) mode and the commanded A/F will change from 14.7 to somewhere in the 13 range. Then a PE vs Time graph will adjust the A/F if you stay on the throttle.... I can give you a real good idea right now what your A/F numbers will look like when you floor it.



Only true for stoich. The narrowband won't help you outside of that.



Your fuel trims will likely be jacked. LTFT's max out at 25% I believe. STFT's at 99%.

This was an incredible helpfull post. Thank you!

By my math, 6000 RPM gives about 20ms between fires. 3,000 (fire on every other revolution) divide by 60 seconds = 50 firings per sec. 1 sec divide by 50 is .02. So if the injectors are stuck on, wide open, never closing, that's equiv to a 20ms pulse width. 80% duty cycle would be 16 ms. (.8 * .020=.016)

So to be inside proper margins with wiggle room, 16ms should probably be the upper limit. I'm seeing close to that on normal fuel.

The stock AFR commanded is 14.7. At power enrich it goes to 12.2 commanded A/F according to the scan gage. Does it try to enrich further as times goes on in that mode?

The biggest question that I'm wrestling with is how to make the car go from no ethanol to 85% ethanol without tuning it each time, and without changing the PCM. Anyone worth a hoot can do some math, then trial and error out a good tune on one type of fuel, and with enough experience, one can crank out a really good tune. Until the fuel changes. Flex fuel vehicles do it for every mix from zero to E85, and modern ones do it without an alcohol sensor.

So basically by watching long term trim tables, the amount of alcohol is estimated and the A/F is set accordingly. I don't know that a stock PCM's program can do that.

Is it just as simple as always chasing "lambda 1" and having the amount of injector to make it a reality?

[peppermill]

Originally Posted by SpyhunteR

Give me your car and let's go play with it on the dyno.

If I were less than 8 hours away, I'd load it on the trailer and be there later this week. I have no desire for a 24 hour one way road trip right now, esp with the price of diesel what it is. :-)

[SpyhunteR]

so the car runs lean, just like i said.

i'm not shocked.

[peppermill]

Originally Posted by SpyhunteR

so the car runs lean, just like i said.

i'm not shocked.

When you dissagree with me, you want numbers to back it up. When I don't have a number but have the same gut instinct as you, you act like you've proved something. You're a real piece of work.

I drove 300 miles with some type of spark plug issue, and still got 24MPG on fuel that is one dollar a gallon less than regular. I know I was leaning under load, I could feel it, and won't dispute it. (because I said I was!!) But when not under load, I don't think I was lean. If E85 does 30% less milage, and the best milage one could possibly acheive on a road trip is 30-32 MPG, then my average condition was not really lean. On average, and more than 95% of the rest of the time, I'd say it was pretty close to stoch. An E85 conversion for a Grant AM GT might be as easy and lengthening the throttle cable to prevent any more than 50% throttle.

(I bet no one has ever made that mod suggestion on this board before! "here's how to make the car go slower...")

And is it bad to lean out at low engine loads? Does it hurt anything? I know running WOT lean causes problems, that's a no brainer, with plenty of evidence to back it up. But at less than 50% throttle on 100+ octane fuel, is lean really all that bad? At low engines loads (means: we're not melting pistons and valves), as long as the engine isn't misfiring or knocking, is running lean bad? Other than the EPA, is there some reason that we all have to run around at 14.7:1 rather than 16:1 or 20:1 air fuel ratio?

Here's a quote you won't see. Ever:
"Man, I had the cruise set at 55 and leaned out and blew a head gasket and cracked a piston! I must have been going 53MPH at the time!"

The scan gage is installed. The fuel barrel is set up. Just leveled it last night. Today I place the order for 300 gallons of E85. I'm splitting the cost with a friend who's blending it 50% with normal fuel in his new older model year Silverado.... one year before they were Flex Fuel Vehicles.

[AleroB888]

Originally Posted by peppermill

The biggest question that I'm wrestling with is how to make the car go from no ethanol to 85% ethanol without tuning it each time, and without changing the PCM. Anyone worth a hoot can do some math, then trial and error out a good tune on one type of fuel, and with enough experience, one can crank out a really good tune. Until the fuel changes..........................
......
So basically by watching long term trim tables, the amount of alcohol is estimated and the A/F is set accordingly. I don't know that a stock PCM's program can do that.

Originally Posted by peppermill

.......I can definitely see why it's easier to just drop in slightly larger injectors, and let the PCM fuel trim table adjust down to near it's "Bank 1 too Rich" limit on E0, so it just barely approaches the "Bank 1 too lean" limit on E85 and run with a stock PCM.

But where's the fun in that?

It's been a few years, but I changed from 19 lb. stock injectors to 28 lb. Trailblazer injectors without retuning the PCM. Within minutes of running, I got the expected "rich" codes set, but deleted them with a handheld scanner. After maybe an hour of driving, the codes did not return, and idling and drivability were not effected. (I am also at a high altitude).

Not to keep harping on this, but it's such an easy switch. It would be essential information to find out just how much injector the stock PCM can compensate for, without retuning.

[Mike Jung]

Originally Posted by peppermill

...Today I place the order for 300 gallons of E85. I'm splitting the cost with a friend...

While I don't agree with you blending of E85...

Let me just say this:
Be careful storing the 300 gallons of E85.
Or you will contaminate it with water !

[SpyhunteR]

Originally Posted by Mike Jung

While I don't agree with you blending of E85...

Let me just say this:
Be careful storing the 300 gallons of E85.
Or you will contaminate it with water !

, I think you just predicted the end of his engine.

[Upshift]

Originally Posted by Mike Jung

While I don't agree with you blending of E85...

Let me just say this:
Be careful storing the 300 gallons of E85.
Or you will contaminate it with water !

Gulp water :|

Especially since this time of year is pretty humid.. Ouch

[SpyhunteR]

yeah E85 has this awesome ability to absorb moisture and contaminate it.

[Upshift]

Originally Posted by SpyhunteR

yeah E85 has this awesome ability to absorb moisture and contaminate it.

Damn, that's not the type of fuel you want to have if you have the bad habit of always leaving your tank between halfway or near empty all the time.. Concidering that a tank that isnt full has the nice habit of trapping moisture.

But im glad to ahve learned that. Now i know for sure i wont try E85, not that I ever had the intention to anyways.

[SpyhunteR]

Originally Posted by Upshift

Damn, that's not the type of fuel you want to have if you have the bad habit of always leaving your tank between halfway or near empty all the time.. Concidering that a tank that isnt full has the nice habit of trapping moisture.

But im glad to ahve learned that. Now i know for sure i wont try E85, not that I ever had the intention to anyways.

well it is safer in your tank then it is storing 300 gallons of it in your garage.

[cardude007617]

besides doesnt a plastic tank deter condensation?

[Malaclypse]

Originally Posted by cardude007617

besides doesnt a plastic tank deter condensation?

Doesn't matter when the EVAP vent solenoid is open with the vehicle off. This is to prevent pressure buildup in the fuel tank from evaporation.

The moisture has to travel through a charcoal canister before it gets to the tank, but I'm sure some moisture still makes it in there.

[Upshift]

Originally Posted by Malaclypse

Doesn't matter when the EVAP vent solenoid is open with the vehicle off. This is to prevent pressure buildup in the fuel tank from evaporation.

The moisture has to travel through a charcoal canister before it gets to the tank, but I'm sure some moisture still makes it in there.

So basically, no matter what kind of tank, he's still getting some moisture in his tank, and it will more then gladly contaminate his E85. Fun