Gasoline + Ethanol

[SplatterTone]

Wondering how warming up a coil could cause it stop sparking, a little research turns up this. Interesting, I think.
http://www.newton.dep.anl.gov/askasci/e ... g99514.htm

[tubatom91]

I am leaning towards the carb. because the car has a brand new ignition coil in it. I dont think it is anything electrical because last year we replaced the rotor, points, distributer cap, spark plug wires, and spark plugs. The fuel lines are new and the pump is new. My Grandpa had this very same issue on his '28 Whippet. I have a can of starting fluid in the trunk, it gave a few sputters but quit...just like it did before we replaced the pump. I am going to order the rebuild kit from Kanter auto, I have had good luck with them.

[Todd S. Malicoate]

Well, yeah...if the starting fluid gave you a few sputters, then you probably had good spark. I still don't understand why you were able to start it pretty much right up after it was towed, though...anybody with an older car with a mechanical pump knows it takes several cranks to get fuel to the carburetor, which you say didn't have fuel in it. Weird.

Anyhow, good luck with your carb rebuild!

[tubatom91]

Here is a list of things I have replaced (to avoid confusion on your end and mine ):
fuel pump,fuel lines,fuel filter,battery,points,rotor,dist. cap,spark plugs,spark plug wires,headlight,key(s),and ignition coil. I know that when we replaced the coil we used a voltage tester (a little yellow box with two wires coming out of it) to see if there was enough power. There was. I know that the car has a rather complicated ignition system IMO. It is a floor switch but not a seperate button. When the key is turned a little silver toggle comes out (I pump the gas pedal a few times at this point) You flip the switch to on and push in the gas pedal as you are "flooring it" the starter kicks in. When the engine starts a vacuum switch disengages the starter switch in the pedal. The car also idles fast when warming up but when you tap the gas pedal a linkage drops the idle speed down and the car runs smooth as silk. I figure this info might stir some minds.

P.S. I know how hard it is to diagnose a problem without the car in your garage. The car isn't even in my garage!

[tofu]

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[tubatom91]

I have been in a car that vapor locked. It was in Nashville Tennesee in the middle of summer the high for the day was around 102 degrees, 100% humidity. We were just starting to head back to the hotel after a long day of tours and driving (Car club tour). The 1916 7 passenger touring car that we were in has a 6 inch exhaust that runs under the passenger side floorboard and then under the gas tank that is mounted under the front seat. YOu could pretty much feel the gasoline bubble under your seat. And about a mile later the car crapped out. The way that car beheaved and the way mine behaved seemed to be different. I think the float stuck on the intake side of the carb. Last summer we tried to start my grandpas stakebed truck. The float sutck on the output side and flooded over and onto the floor. The engine backfired and lit the front end of the truck on fire....needless to say we keep a fire extinguisher handy and in every car.

[Rick Denney]

I am leaning towards the carb. because the car has a brand new ignition coil in it. I dont think it is anything electrical because last year we replaced the rotor, points, distributer cap, spark plug wires, and spark plugs. The fuel lines are new and the pump is new. My Grandpa had this very same issue on his '28 Whippet. I have a can of starting fluid in the trunk, it gave a few sputters but quit...just like it did before we replaced the pump. I am going to order the rebuild kit from Kanter auto, I have had good luck with them.

I'm a little curious about the starting fluid only causing a bit of rough sputtering. If the fuel flow was cut off, the engine should run fine (for a while) on starting fluid as long as you spray it into the throat--you are not using the carb for anything with starting fluid except as a path to the intake valves. If it would only stumble roughly, then I wonder if it's not a matter of fuel starvation but rather flooding.

Now, THAT is a problem that is common on older cars, and it IS a problem with the float valve. Rust and dirt particles keep it from sealing, and the float bowl overflows. This problem, unlike fuel starvation, is worst at idle, when fuel demands are the least. The fuel will often overflow the float bowl and run out on top of the engine, in addition to dripping into the throat and causing the engine to flood. This will cause the engine to run rough at idle and possibly die, and because it's flooded, it will not restart until the excess fuel has evaporated. Then, it will start up again just fine. That sounds more like your symptoms.

But you must find the source of the dirt, and I doubt it's ethanol. I would be much more suspicious of rust in the fuel tank--I've never known a really old vehicle that didn't have a problem with rusty tanks. Humidity is inevitable in the fuel tank, and as temperature changes, the tank will breathe humid air in and out through the vents provided on older systems. Moisture accumulates and that causes the steel tank to rust. Ethanol in the fuel actually helps with this by absorbing some moisture so that it can be burned in the engine instead of being allowed to collect in the tank.

Rebuilding the carb is a temporary solution, just as installing a new pump was a temporary solution, if the tank is full of rust. The only solution in that case is to replace the tank, I'm afraid. I have had to do that on my GMC motorhome, and it was still the single most expensive repair I've made--the new tanks (yes, there are two of them) were large and custom-made. I also have had to replace rust-jammed filter socks on all GM vehicles that were older than about 15 years, though that too is a temporary solution.

Don't just throw parts and rebuilds at it. Understand the problem. Cut open a fuel filter--if you see red particles jammed into it, then you have rust. Remove the hose from the pump, and blow compressed air back into the tank (dial the compressor regulator down to about 15 psi, remove the filler cap, and inject the air in short 1-second bursts). That will sometimes blow a clogged filter sock off the sender, re-establishing fuel flow (for a while). But the problem is the rust, not the clogs, and removing the clogs will only provide temporary relief until it clogs again. At the very least, install a good (large) inline filter between the tank and the pump to protect what you have done with the pump and the carb, and resign yourself to replacing that filter very frequently.

Rick "been there; done that" Denney

[Todd S. Malicoate]

Good post, Rick...perhaps a bit too good.

Diagnosis is the key to solving problems, especially in older vehicles like this. Unfortunately, it's much easier to "go with the gut" and throw parts at it.

The only thing I would add is that, if it is rust in the gas tank, there are some excellent products for restoring an old tank. The one I recommend to my customers can be found at http://www.kbs-coatings.com.

Just please, don't yell at your parts guy if/when he gets you exactly what you asked for and it's doesn't fix the problem.

Todd S. "also been there and done that" Malicoate

[tofu]

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[tubatom91]

To make things clear. This is a Buick that has never been restored. The car has under 40K Miles. and It has never been off the frame. (Since tofu mentioned restoration)

[tofu]

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[Todd S. Malicoate]

I didn't realize somebody was still selling no ethanol gas. I assumed that the gubmint had outlawed it for cars. Is it just Valero branded stations or do Valero's other brands sell it as well?

Here in Stillwater, it's not even all Valero stations - just one.

As far as the government regulations, I think it's a state by state mandate. Oklahoma apparently doesn't require ethanol in the gas.

[Rick Denney]

I didn't realize somebody was still selling no ethanol gas. I assumed that the gubmint had outlawed it for cars. Is it just Valero branded stations or do Valero's other brands sell it as well?

Here in Stillwater, it's not even all Valero stations - just one.

As far as the government regulations, I think it's a state by state mandate. Oklahoma apparently doesn't require ethanol in the gas.

It depends on each regions air quality improvement program, which is part of the statewide air quality improvement program. Metropolitan areas that do not meet air quality requirements are termed "non-compliant" and must enforce the use of such additives as oxygenate. The alcohol acts as an oxygenate, and in that role it's a lot better than the alternative, which is the very toxic MBTE. But whether oxygenated fuels really make the systemic improvement claimed for them is another debate altogether.

Most rural regions do not require oxygenated fuels. And even where it is required, it will be affected by the season.

Which brings me to another issue: Vapor pressure. Summer-blend fuel has a different vapor pressure than winter-blend fuel to help prevent vapor lock and still provide clean operation. And summer-blend fuel may require different oxygenation to account for the higher incident of stagnant conditions and ozone alerts. For our daily drivers that get a fresh fuel tank every week or two, it doesn't much matter. But for vehicles used only occasionally, we may be burning winter-blend in the summer or vice-versa, and winter-blend fuel can be subject to vapor lock to a greater extent than summer-blend fuel. It's something to consider. Of course, if you pour a fuel stabilizer, such as Sta-Bil, into the tank to help the fuel last until the next use, you have turned your gasoline into gasohol.

With the GMC motorhomes, there have been reports of the vapor pressure being so low that mere road heat is enough to start boiling the fuel in the tanks (and this effect has been described in this thread, too). That can cause fuel starvation for sure. But it acts like fuel starvation--the engine does not run well when being asked to make power, but will idle smoothly. I've had that problem on my GMC from time to time, even using an electric fuel pump back by the tanks. For old cars that pull fuel from the tanks using an engine-mounted fuel pump, the slight negative pressure applied to the fuel can greatly lower it's vapor pressure and boiling point, and even moreso if the sending unit/pickup is restricted in any way.

For the unrestored Buick, it would be worth the trouble to drop the fuel tank, remove the sending unit, and inspect the interior of the tank for rust. As I said before, this can happen just sitting there because of the way the tank breathes in moisture-laden air with the changes in ambient temperature. It's a required step in keeping a really old car running reliably. Also, make sure you use Sta-Bil when you aren't going to be using the fuel in the tank for a long time. It's better, though, to give old cars reasonably frequent exercise. Cars driven frequently will survive the ages better than cars that just sit.

Rick "thinking a frame-off restoration of a GMC motorhome, while not that uncommon, is still a really big job" Denney

[Todd S. Malicoate]

It depends on each regions air quality improvement program, which is part of the statewide air quality improvement program. Metropolitan areas that do not meet air quality requirements are termed "non-compliant" and must enforce the use of such additives as oxygenate. The alcohol acts as an oxygenate, and in that role it's a lot better than the alternative, which is the very toxic MBTE. But whether oxygenated fuels really make the systemic improvement claimed for them is another debate altogether.

Most rural regions do not require oxygenated fuels. And even where it is required, it will be affected by the season.

That makes sense to me...what it doesn't explain is why fully 95% of the stations around here do use ethanol in their gas. I suspect a profit margin explanation for that.

I would think that the demand for ethanol-free gasoline is very high, especially considering the bad press ethanol is getting. However, the only three stations that I know of in the county that sell it are very small outfits - they all charge just a bit more per gallon for their ethanol-free gas. Something is keeping the big boys from selling a product that the public very clearly wants to buy.

Todd S. "clean air, open spaces...it doesn't get much more rural than this" Malicoate

[Rick Denney]

I would think that the demand for ethanol-free gasoline is very high, especially considering the bad press ethanol is getting.

Bad press? I don't see any of that around here, unless you mean the problem of ethanol use for fuel driving up corn-based food prices. Everyone around here still seems to be in love with it.

Ethanol is a safe oxygenate, and if your state requires oxygenated fuels (I don't know, but I do know that some states do, with California being the most famous example), ethanol is as reasonable as anything else and a lot less toxic than MTBE.

Ethanol is found in most of the fuel around here, too. When I go outside the DC Metro area into counties that are not included in the oxygenated fuel program, low-price stations still seem to use gasohol, perhaps to make those lower prices possible. It's so hard to keep from buying gasohol these days that I've stopped trying. I could easily burn more gas than I would save by finding and using gasoline without ethanol. My motorhome seems to run fine on it, though I did have what I suspect was a vapor-lock or related issue when driving it up a steep road at very low speed (read: maximum power requirement-to-underhood temperature ratio) at about 4400 feet above sea level. My vacuum gauge read about 20% lower than normal on top of that hill. The engine would occasionally die, but would restart instantly if I waited a few seconds before turning the key. Just in case, I'm replacing the electric fuel pump, because the old one really is old and I'm not exactly sure of its brand or specifications.

Rick "who'd rather have ethanol than pinging or MTBE in the ground water" Denney

[Todd S. Malicoate]

Bad press? I don't see any of that around here, unless you mean the problem of ethanol use for fuel driving up corn-based food prices. Everyone around here still seems to be in love with it.

Yep. Bad press. Plenty of stories about corn prices, world starvation, and bad performance from vehicles. I'm not saying I believe any or all of them, just that the bad press is there. I talk with folks every work day about cars and car problems, and lots of people here don't like the fact that their cars get lower mileage with fuel that is costing more and more. The only press I see that is positive about ethanol is from elected officials patting themselves on the back for "doing something" about the "energy crisis" by converting all of us over to "alternative fuels."

I've reported my results on six tankfulls earlier in the thread. You can have the ethanol...just continue to give me the choice to pay a bit more for ethanol-free, Mr. Senator, sir. 3-4 extra mpg isn't peanuts to me.

Todd S. "who suspects a geographical reason for the difference in Rick Denney's and my take on the press coverage of ethanol" Malicoate

[tubatom91]

Thanks for the info on the in-tank issues. I need to drop the tank anyways to fix the sending unit (my gas gauge doesn't work ).

[tofu]

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[lgb&dtuba]

....because the freakin gas tank is in the cowl just above your legs and a foot in front of your chest! I try to not think about that when I'm driving one.

Better there than where the gas tank is on a motorcycle

[Rick Denney]

Todd S. "who suspects a geographical reason for the difference in Rick Denney's and my take on the press coverage of ethanol" Malicoate

Studies I've seen show a reduction in fuel consumption of about 10% with oxygenated fuels. The oxygenate does not have to be ethanol, though that's what it usually is these days. I always get better mileage with "country gas" than with "city gas". I just have to drive so far to get country gas that I use up the improvement. My wife, however, fills up where she works, which is far enough west of DC to make country gas an option. She pays less for it out there, too.

If you want to know why politicians like ethanol, you don't have to go any farther than a review of the farm lobby. But we aren't allowed to complain about the farm lobby, are we?

Rick "who spells farm lobby 'A-D-M'" Denney