Lets discuss Ethanol

[Blue Bowtie]

E-10 should not be a problem. If the engine is now running rough, it is likely due to the ethanol cleaning out the fuel system. The sediments, rust particles, additive deposits, and other random contaminants should be captured by the fuel filter. However, once the filter is slugged, or if it is damaged or inadequate to filter fine particulates, these contaminants can reach the fuel injectors and clog the inlet screens, or worse, clog the injector pintles or spray tips/orifices. I'd suspect the rough running is due to a fuel delivery problem, and not the fuel itself. If the problem persists after several tankfuls of fuel, the fuel system may need to be checked.

[Chris Stewart]

Alky's not a cleaner. It does attract water which will corrode your steel and aluminum parts.

[ericn1300]

Originally Posted by Blue Bowtie

Well, that's at least half the science. Granted, ethanol by itself has less HEAT energy than refined gasoline. That doesn't mean less energy. Hydrazine has far less heat energy than gasoline, but you don't see gasoline being used as a rocket fuel. Kerosene (diesel) has more heat energy than gasoline, so why aren't you burning that in your car? Coal has even more heat energy. Why aren't the Consumer Reports "experts" using coal in their cars?

LOL, hydrazine and coal are solid fuels and very hard to to run thru my 16 year old Bravada without some major modifications. Kerosene does have more energy than gasoline but I can't use that either. Stick to the thesis of the thread: Ethanol blends vs Gasoline.

Originally Posted by Blue Bowtie

The universities of Iowa, Indiana, and Illinois have a lot more empirical data on ethanol fuels than Colorado, dating back to the mid-1970s. Colorado, despite their beautiful landscapes and friendly population, just doesn't have any history with grain ethanol.

I've been there, seen the beautiful landscapes and the natives were quite friendly, with the exception of my ex-wife, but I would love to see the data excluding or over riding their research, have any links with empirical data?

Originally Posted by Blue Bowtie

there is little doubt that site was produced with the "assistance" of the liberal arts and journalism departments of a PAC 10 school.

Before you try to defend them, remember that these are the same people who handed us the likes of Nancy Pelosi nd Harry Reid. 'Nuff said?

If your idea of academic excellence is based on the athletic conference your school was in then it's no surprise you just ”sat through physics and chemistry classes”

Nancy and Harry actually fought the farm lobbyists that promoted the tax breaks the Republicans so greedily applied for.

[ericn1300]

Originally Posted by Blue Bowtie

Yes. Make sure the pump is capable of delivering fuel at a significantly higher pressure than the setting of the FPR, and vapors will be purged on the first two-second prime cycle of the fuel pump (just the way the factory designed it).

If the pump is weak, there is not much else to be done other than to relieve pressure and hope the pump can push some liquid fuel through the line faster than it can explode into vapor in the hot lines. you can insulate/isolate the fuel lines with heat shielding if the problem becomes more than a periodic nuisance.

Strange that you would experience this with ethanol, but at 100ºF, I have no such problems on any vehicle, including the potentially worst offender, a CPI system in a van, where all the heat is contains in one, compact area.

If the vapor pressure of the blockage is higher than the fuel pump pressure and the blockage is at a height greater than the fuel pressure relief valve (FPR) your theory goes down the drain. Vapors rise and don't go down hill until forced down. 60 lbs of fuel pressure ain't going to do it.

[Wags391]

Wow. This thread is getting political rather than helping. Come on guys, any ideas besides higher octane gas?

[ericn1300]

Originally Posted by Wags391

Wow. This thread is getting political rather than helping. Come on guys, any ideas besides higher octane gas?

Actually, Ethanol is a higher octane than un-blended gas but that's a whole 'nuther discussion. The only thing to do about it is to call or write all your elected officials and more importantly contact your state AAA club. They lobby on your behalf and if they get enough complaints they will pressure the pol cats on your behalf

[Chris Stewart]

Maybe the mix is better now...I've read some stories where too much alky was put in gasoline causing problems when it was first put to use.
Just to be fair, all my gassers did fine this summer except for the garden tractor which acted like it was running lean but recovered when I pulled the choke a little...most likely the carburetor needs taking apart and cleaned. The weedeater did fine also.

[Blue Bowtie]

Originally Posted by ericn1300

LOL, hydrazine and coal are solid fuels and very hard to to run thru my 16 year old Bravada without some major modifications. Kerosene does have more energy than gasoline but I can't use that either. Stick to the thesis of the thread: Ethanol blends vs Gasoline.

Oh, c'mon... You're not trying hard enough. (Actually, hydrazine is a liquid, but we get the idea.) The point was, and remains, that Btu energy is NOT the whole story, despite what Consumer Reports might proclaim.

I've been there, seen the beautiful landscapes and the natives were quite friendly, with the exception of my ex-wife, but I would love to see the data excluding or over riding their research, have any links with empirical data?

Sorry you found one of the less-friendly natives. I'm sure they are the exception, and are not limited to Colorado. At least you survived with your sanity. I'll try to compile what I have gathered and forward it if you are really interested. I did quite a bit of research on the topic about four years ago when I converted my half-truck to running E-85. Colorado was a good on-line resource, but by no means the ultimate authority. I'll have to scan what I've gathered. I should have done that a long time ago, since this topic arises frequently, and is likely to only become more relevant as everyone else catches up to ethanol blends. Remember, I've been doing this in a practical sense since 1976 with no serious trouble in any vehicle. I have had some initial problems, such as the OP is experiencing. Most of that was with carbureted engines, but even those came around, and were ultimately even easier to adjust for the changes.

If your idea of academic excellence is based on the athletic conference your school was in then it's no surprise you just ”sat through physics and chemistry classes”

Nice catch, but even through osmosis I retained a few things. FWIW, no one from the Big 10 should be bragging too much about their athletics programs. I was speaking strictly about science and academics.

Nancy and Harry actually fought the farm lobbyists that promoted the tax breaks the Republicans so greedily applied for.

That's not so much of an argument as it is more evidence of them fighting a losing battle - Something for which they have demonstrated acuity. Never forget that our new "Change" president-elect is heavily vested in renewable energy (read "ethanol") and makes his home in Chicago. Whether or not you agree or subscribe to the science, it isn't going away any time soon.

As for the previous comment regarding food prices being escalated by the use of grains for fuel (I'm not sure who posted it), remember that a $4.00 box of corn flakes contains a whopping total of 14¢ worth of corn. The rest is labor, operating costs, transportation, and marketing (or greed). That was the value when corn was $4.35/bushel. and since it is now back to under $3.50, there is even less cost in that box. Did you see the prices lowered by 25%? Didn't think so. For those worried about food prices, do some more research. Given the amount of mash corn grown (which can't be used for much else) versus feed corn, the volume of feed corn hasn't been reduced enough to drive prices one way or the other. CBOT prices have been driven by the anticipated energy prices required to dry, deliver, and process grains, and not the availability of grains themselves. Stop listening to politicians and their hip-pocket news media, and start researching.

If the vapor pressure of the blockage is higher than the fuel pump pressure and the blockage is at a height greater than the fuel pressure relief valve (FPR) your theory goes down the drain. Vapors rise and don't go down hill until forced down. 60 lbs of fuel pressure ain't going to do it.

Diagram that concept and observe it. The relief line is open all the way back to the tank. Once liquid pressure is greater than the relief valve (FPR) setting, anything in the line will be pushed back to the tank, whether it is a vapor, gas, liquid, or solid (small enough to pass the regulator disc valve). The return line does indeed travel back downward to the tank, but only a total of about 20". That only adds about 0.65 PSI to the pressure required to flood the line with fuel. A sequential CPI system pump should be able to dead-head at least 71 PSIG, which is more than adequate to purge the lines. Even though a vehicle will run with only 61 PSIG, the pump should perform better (as it is designed to). If you are experiencing vapor lock (and it seems that you may well be) I'd test the fuel pressure with the return line closed to measure peak pump pressure. I understand that a small volume of fuel in the injector pod may turn to vapor, but the design volume of the pump (minimum 4 LPM) should be able to displace that easily on a prime cycle.

[Blue Bowtie]

Originally Posted by Wags391

Wow. This thread is getting political rather than helping. Come on guys, any ideas besides higher octane gas?

Yes, about 4-5 posts ago.

Have you tested fuel pressure? Checked/changed the fuel filter? As previously mentioned, the ethanol will start cleaning out all manner of junk from the tank and lines. The filter is your first line of defense. Since the vehicle has evidently not previously used ethanol blends, this process will continue until the system is clean. Get familiar with the filter change procedure, since you might be doing it more than once until the system is clean.

Don't blame the fuel. It's only cleaning out what the other fuel left in there. You should see what happens to a 1950s or 1960s vehicle when ethanol is first run through it. Been there.

If there is already sediment in the injector pod inlet screens, it may be time to pull the pod and clean it. If you have to go that far, be absolutely certain you have a good filter installed, since you probably don't want to be cleaning the injector pod again.

Another thing to remember is that alcohols are hygroscopic, meaning that they have an affinity for water. Given the relatively high humidity present in Florida, that means that some water will be more likely found in the fuel. Fuel tanks are vented, and some of that water will enter the fuel as it is stored. The only thing you can do to counteract that is to purchase fuel where there is a lot of traffic, and the fuel will theoretically have less time in the tanks to absorb water.

Another important step is to be sure your fuel system is sealed. If you have an unsealed system, the PCM should be setting an EVAP related error code.

[ericn1300]

Originally Posted by Blue Bowtie

As previously mentioned, the ethanol will start cleaning out all manner of junk from the tank and lines.

Another thing to remember is that alcohols are hygroscopic, meaning that they have an affinity for water.

Bowtie is correct. Ethanol will transport water and water soluble debris thru the engine that would otherwise be left behind. The water carried by the ethanol will also tend to blast out some of the carbon build up, a notorious problem on the 4.3 engine. Keep the EGR valve clean by installing a screened gasket to block the larger chunks that bind off the pintle.