Has the EPA finally killed my cars?

[Stripgear]

I live in central Texas and have a '48 Super, '62 Skylark V-8 (A/C), and an '82 RX-7 (A/C and electric fuel pump), all with carbs. The Skylark and RX-7 both have vapor return lines. I have had all of these cars over 15 years and have never had any concern about driving them anywhere, anytime. I've never had any problems with heat EVER until last year.

Starting last summer, anytime the temperature is over 100 degrees, when I get off of the highway and get into an idling situation (like in line at a car show or a parking lot) I better get where I need to go and get parked fast. If I don't, it's going to start to miss and finally stall. It's not going to re-start. When I open the hood and take off the air cleaner, I can see the gas boiling over into the venturis. I've never gotten stranded, I've just got to wait 20-30 minutes and then I can go on my merry way.

I've used different gas stations and I use premium in the '62. I kind of ignored it with the "old" Buicks, but when the "modern" RX-7 did it this week (at 103 degrees) I really bothered me. I think they've finally got the vapor pressure of the new gas so low that carbs just can't handle it in triple digit temps.

Any comments? Is this happening to anybody else?

[JohnD1956]

Yes, Vapor Lock is an issue these days, but that does not mean something can't be done.

Insulate your gas line from the pump to the carb. Insulate it by moving it away from hot areas of the engine. does it route next to ( or touching) the thermostat housing, corner of the head, valley next to the intake manifold? If so, gently bend it away from these points and try again. Lastly I would consider wrapping the line with something, although I am not in a position to make a tested recommendation.

[buick man]

Yes it is the ethanol. To advert this one must pressurize your system via an electric fuel pump along with a in-line pressure gauge/switch. The line is pressurized from the tank to the electric pump along with a return line to the tank for bleed off. That will cure the problem but not the crappy E10 or E15 which is a poor oxygenate in proportion to it's power of combustion and mileage yields.

To cure that, one has to be more selective on who one votes for nowadays for your state and federal representatives. Try voting for a 3rd party candidate next time and perhaps together we can repeal the incentives and tax giveaways to corn growers for ethanol production while the rest of the world is heading for food famines.

[NTX5467]

I believe the fuel is boiling in the bowl from the combination of several things. One could be the vapor pressure of the fuel, but I don't believe that spec has changed for us in TX in several years, even with ethanol'd fuels. With the length of our summer temps, I'd think that fuel blends would have been optimized for them, rather than you getting "cooler weather" blends that would be more likely to act as you've mentioned.

Certainly, the higher ambient temps are what they are, but what about the ambient underhood temperature on your vehicles? Are the cooling fans working and coming on when they should, if so equipped, or is the engine-driven fan working as it should?

There can also be two sources of the "boiling fuel". One, as John mentioned, is the fuel lines being a little too close to heat-producing sources. In that case, some ThermoTec wrap might be in order. I believe they have some "tubes" for fuel lines. Seems like I've seen it listed on the O'Reilly's Auto Parts website? In this scenario, the fuel would become gaseous in the lines before it got to the carb, which just let it dispense itself into the venturi area of the carb, uncontrolled, it seems, by the needle and seat in the float bowl.

The other scenario would be that once the liquid fuel gets to the carb, the carb's heat makes the fuel boil. In this scenario, making sure that the carb's base gasket is an OEM-spec gasket rather than the thinner ones many rebuild kits have, would be highly important. Also, for the later 4bbl carbs, GM used to have an insulator gasket with a large piece of aluminum sandwiched between two gaskets--one for the Q-Jet and one for the Holley 4bbl. Similar gaskets are now available elsewhere. The "famous" Mr. Gasket carb insulator gaskets was a multi-layer sandwich of aluminum and gaskets to do the same thing, BUT if you were not extrememly careful in re-torqueing the carb nuts, you could crack the carb's baseplate due to uneven torque--not good. In some drag-racing-oriented websites, you can also purchase wood spacers to go between the carb and the manifold, with gaskets, for heat insulation of the carb. This could well put the carb too high for good hood clearance!!!

The reason the car starts to miss is the over-rich fuel mixture. Rather than drive normally as you slow down, it might be good to also manually put the trans in the next lowest gear as you start to slow down from highway speeds. This would keep the engine-driven fan turning faster and keep the latent heat buildup under the hood decreased. Not necessarily to gear it down as a trucker might do to save the brakes, but to keep the engine running a little faster than normal to keep more air moving around under the hood. I might suggest aiming for the equivalent of "fast idle" (i.e., about 1400rpm). Also, when the vehicle is stopped, putting the trans in Neutral and discretely raising the rpms can help for the same reason. Key thing is that with the vehicle running down the highway, there is a certain amount of heat being generated by the engine and such, with sufficient air flow to keep it all cooled to acceptable levels.

As you start slowing down, it takes a little while for the heat to similarly decrease, yet with lower airflow through the engine compartment. Plus, heat radiating from the roadway increases its effect upon the vehicle, too.

Or, you can add a "pusher" underhood fan in front of the radiator or a/c condenser, activated to come on at about 180 degrees or so. If the fuel tank is exposed under the car, painting it silver might help keep that fuel area a little cooler, too, as it would reflect more of the pavement's heat than it would absorb (if it was black with undercoat or paint).

Unfortunately, determining where the base problem comes from is important. Fuel in the fuel line boiling due to heat radiating from the pavement or other operating systems of the vehicle? Fuel in the carb float bowl being overly affected by the heat? Cooling system performance has slowly deteriorated, but is not totally out of spec at this time? Cooling system performance not being strong enough to overcome "tail wind" situations when moving slowly or when stopped and idling?

Just some thoughts,

NTX5467

[NTX5467]

To cure that, one has to be more selective on who one votes for nowadays for your state and federal representatives. Try voting for a 3rd party candidate next time and perhaps together we can repeal the incentives and tax giveaways to corn growers for ethanol production while the rest of the world is heading for food famines.

The whole ethanol use specs, total gallons of ethanol production going into gasoline due to legislative mandate, was done during the President George W. Bush administration. The second of his two terms, I believe. Term limits got him.

In the mean time, DO email or call your elected Federal legislators, even ones outside of your district, and express your feelings about how E10 is already negatively affecting your vehicles and off-road power equipment. Therefore, you might suspect that E15 will cause an even greater financial burden in keeping these engines running as emissions-free as they can. The loss in fuel economy is one significant thing . . . with more loss in economy with E15 and very little additional emissions decrease benefit.

On Ed Wallace's radio show, "Wheels" on KLIF 570AM this morning, local Federal legislator Michael Burgess was mentioning that he has to take his weed whacker in each year for "work" so it's useable again, due to the ethanol in the gasoline we have in North TX. The repairman mentioned that he sees a lot of that sort of thing now.

Regards,

NTX5467

[Guest rsd9699]

You have waited too long - the California nuts have taken root in this entire country - best you get out your fiddle and play while America burns.

Ron

[Guest NikeAjax]

HEY, come on guys, can we please keep this a POLITICAL FREE zone! We're here to help others with their cars, and not point fingers at the brain-damaged chimps running the country. Try to think of it this way: you may be insulting someone who can help you, lets keep this about the cars!

Thanks,

Jay

[Stripgear]

Thanks,

The tubing looks interesting. Here it is:

Thermo-Tec : Heat Sleeves

Scott

[Guest NikeAjax]

An old timer trick is to add a bit of diesel fuel to the mixture of gas, or you can use Marvel Mystery oil too: it helps to keep the gas from peculating as much, it stabilizes it. I think the mixture was one quart to every ten gallons. A friend of mine with a Pierce Arrow taught me that one.

Jaybird

[Guest rockindubya]

Since neither of my oldies are running right now, I don't have that issue. But stored E-10 draws moisture like crazy, from the minute they blend it.

Some areas, (check your local marinas), have ethaboil-free gasoline.... check this link... <http://pure-gas.org/index.jsp?stateprov=TX>

Another point; Since I started juicing my tractor, weed whacker, chainsaw, outboard gas (anything with a carb....two or four stroke) with Sta-Bil, everything sure runs better.... might give it a try...

[Guest rockindubya]

didn't let me put the link in... Google pure-gas texas

[Guest NikeAjax]

Rockindubya, yeah, essentially that's what the diesel fuel does: it, for lack of a better word, gives the gas more, er, ah, viscosity...

Jaybird

[buick man]

All excellent points but I really don't think green california has had anything to do with this. How can it be green if you are consuming vast amounts of raw materials and receiving little to no real world benefits as a society as a whole but for a few in return unless that is if you are part of that "power cliche" benefiting from these insider mandated arrangements. A consolidation of special interests over and beyond the best interests of the nation as a whole.

[old-tank]

Has the EPA finally killed my cars? Not yet but they are trying!

I have fought vapor lock for years in my 55, but with an electric fuel pump near the tank it is manageable. I have a toggle switch that is flipped in anticipation of a vapor lock situation such as sitting in traffic or after refueling.

Your problem is probably not vapor lock, but volatile gas boiling and this year is the first time I have experienced that also. It is not as bad as yours, since there is no stalling. After a 10 minute stop there is excessive cranking required to start and when it does there is roughness and black smoke from the exhaust and the strong smell of gas from the under the hood. Inspection reveals gas dripping from the throttle shafts. A carb spacer cannot be used in my case since the air cleaner is already contacting the under hood mat. The other suggested solutions for vapor lock should also work to solve gas boiling in the carburetor (since the root cause is excessive volatility of the fuel), but they are all useless! I have tried them:

Additives (diesel, kerosene, Marvel, stabil)=useless

Fuel line insulation=usless (at least between the fuel pump and carburetor)

Premium fuel=useless (probably will make it worse since ethanol increases octane and premium fuels will most likely have more)

In addition to vapor lock and boiling fuel all of my carbureted cars have aggravating hesitation, my lawn/garden equipment runs poorly...

Drive 'em while you can since it will only get worse. Modern cars are not affected, we are the minority, it isn't going to get any better...

Willie

[Roadmaster75]

Here's how bad it is here....

ALL gas is ethanol blend in Illinois.

Can't get real gas.

I bought at 40,000 mile Black '73 455 LeSabre Custom coupe 4 years ago from an

elderly couple in rural Wisconsin. A beautiful original car & (They have real gas in Wisconsin)

The car was pristine and I happily drove it home one crisp November day.

After about 3 tankfuls of Illinois' "special corn 'pone" .......

I strolled out to the shop where the 73 was resting on the upper berth of the lift.

I smelled gas .....strong, too! Luckily, the drip pans all worked.

Long story short ...

the 3 short rubber transition fuel lines from the chassis to the tank had COMPLETELY

deteriorated; from the inside, out. Still had GM logos on them, but, after I quickly

replaced them all; I cut them open and found that the insides had all turned to a "black bubble gum" consistency. AFTER 3 TANKFULS! Imagine what ETHANOL is doing to antique car carb, fuel pump, fuel line, and fittings across the country!

Ethanol is the biggest hoax ever foisted on the un-informed populace. Bad science is accepted and embraced by lawmakers.

The damage is being done and nobody cares. Unfortunately, Willie is right .....it ain't gettin' better.

Circle the wagons, Boys!!!

mike

RoadMaster75

[KAD36]

This is a rather frustrating item my car has been battling also, so will share my experience. Two summers ago I actually had my first major incident in hot weather with a complete stall at a traffic light on a 90+ degree day. In the past after idling a few minutes in traffic on a hot day, the car would surge slightly while accelerating up to highway speeds. This was the first time it quit.

Anyway, 2 summers ago I had just replaced the radiator (brand new - the old one was pretty plugged up and had a couple of rows soldered closed), came to a red light after about a 30 mile highway run in 90 deg heat, stepped on the gas to go and the car died. No amount of cranking would get it going. The person behind me helped push 4075 pounds of Buick iron unceremoniously through the intersection (that was a sight), I popped the hood, and the glass fuel bowl had about 1/8 inch of gas in it. Thinking the fuel pump quit, I got a ride home, grabbed a spare known good pump from the garage, swapped it out of the car roadside real time, and still no joy. Dumped a little gas down the carb, it ran for a few seconds and quit. Could not keep it going. About an hour later, it cooled off, tried again, and it started right up. I also noticed the fuel bowl filled up and stayed filled. I zipped home with no issues. Next day same thing - it surged and quit in town after a highway run - so it wasn't the pump. When the car was cool, the fuel bowl is full. When hot, it seemed to fill with air. My conclusion was that, even though I had a 160 thermostat in the car, on a 90+ deg day with the additional heat coming out of a new radiator and blowing back across the engine, it was boiling off the gas somewhere in the system. I disassembled both fuel pumps and inspected for any micro cracks or other potential flaws in the castings (Bhigdogs suggestion) that could expand when hot or leaks at the valves or where the diaphram seats - nothing. They both behaved the same (so it couldn't be the rebuilder? ) So I went the route of the 4 psi electric pump back at the tank with an in line filter on the inlet side, put a fused toggle switch under the dash wired to ignition hot. And I put a 180 deg thermostat back in. The electric pump solved my problems. Prior to the electric pump, I'd park the car in the hot sun, leave it idling in Drive with the emergency brake on, and if I waited long enough, like about 10 minutes, it quit. The temp gauge will just be just above the N at then end of the gauge range when it happens. It would not restart until it cooled. Now, if I jump in the car and hit the switch on the electric pump just as the engine starts to die, the engine will spring back to life. Same with the surging - hit the electric pump and it will smooth right out on the road. In fact, with the electric pump on, as a test I have recently let the car sit in the sun on a 90 deg day for about 45 minutes idling in Drive such that the temp gauge pegged on the H - no issues. I can get in the car with the gauge pegged, drive off, and it will cool right back down to N and be fine. When hot with the electric pump on, the glass filter bowl will only be half full, and you can occasionally see bubbles blow into it, which does annoy me. When the engine is cold or on a cool day, never any bubbles and it fills up to the top. I have also pressurized the fuel lines and checked the rubber flex hose to ensure no air leaks and they are sound - unless there is a leak at the sender, which I doubt as there would be bubbles independent of temperature. BTW - I have the idle set at a steady 525 in drive - 450 was a little too low for my liking and I figured the 525 would help a little with cooling, charging, and fuel flow. Plus, the engine is a little tired and it wont idle smoothly below 475!

I also run 93 octane (timing is set to 8 deg and no detonation), and started adding the blue Marine grade ethanol treatment to the gas. The car will still occasionally stumble from a start - so the accelerator pump needs to be checked just to be sure, but my hunch is same - this gas is for the birds. Got same hesitation on my 4 stroke outboard, and on my daughters car after it sat for about 6 weeks when she was in college - both fuel injected. Ethanol treatment minimized the prolem in the outboard and cleared up the problem in the Outlander. Guess it depends where you get your gas on. I have read reports that say these problems aren't due to ethanol, but sorry - felt like it was isolated and the fix worked for me

[buick man]

Ken a large part of the hesitation problem is that alcohol requires larger jetting as the molecule is larger. Your jetting cannot handle this and the volume increases with temperature. PV=nrT The Gas Law. Where r is the gas constant - if my memory from college physics still serves me right. A pressure gauge just before the carb can also help control the volume expansion of volatiles when temperature increases. See equation.

Ken: Did you install the electric fuel pump in conjunction with your mechanical pump as well and why just a 4 psi pump? Sounds like a good idea.

[KAD36]

Wow - that equation takes me back! Yes you are right - and r is .082 something (from helping my high school kids with chemistry!). Problem is, I can't readily see how to apply it to the problem - thats probably another thread!

I'm disappointed if the stumble on start is from the gas and we have to "live with it". There must be some workaround. Think I will still check my accel pump and maybe the float just to be sure - I'm confident in the idle and mixture settings.

Electric pump - I bought a 4-7 psi unit from RockAuto I think, or Advanced Auto. Plumbed it in line with the mechanical pump. No regulator - just the pump. Only turn it on like Willie said - when you "see it comin" on a really hot day and kick it on ahead of time. It helps with start up too. Run the pump for about a minute after and it avoids excessive cranking and pedal pumping to start it after it sits for awhile and the gas evaporates out of the fuel bowl. The pump is one of those solenoid designs. It rattled pretty good, so I put some additional rubber isolators between it and the frame to keep things quiet. Ran an extra ground wire from the fuel tank sending unit to the frame, as my fuel gauge lost a good ground when I spliced the rubber hose into the metal line (the metal line was an addtional ground path). Normal operation electric pump stays off and the mechanical pump pulls through it just fine. No effect obviously on the vacuum portion of the pump.

Also to Willlies point - no additives I have tried resolved the surge or hesitation problem. I have used Seafoam or Techron with good results in the past if the carb happend to varnish up over winter. I haven't tried any insulation tricks on the line between the pump and carb, but honestly I felt the problem was either at the pump, a leak in the line prior to the pump or in the carb. The fuel lines in my engine compartment didn't pass close enough to the manifold to cause a problem in my opinion.

[NTX5467]

The current issue of High Performance Pontiac (with the black T/A on the cover) has two articles on "new gasoline" and how to make older cars (Pontiacs in that case) run on it.

One interesting thing is the chart of optimum air/fuel ratios for the various levels of ethanol extension. Zero, E10, E15, and E85. I'd already seen a similar chart in a research report done by Ricardo, in Michigan . . . a report funded by an ethanol advocate, so you can probably guess what their conclusions were, with all due respect AND observations.

In short, the optimum ratio for normal gas (no ethanol) is about 14.7. With E10, that drops to 14.2. With E15, it drops to about 13.8. The chart in the magazine article was provided by Rockett Racing Fuels, which also sells (verified) E85 gasoline. E10 with normal jetting will be reasonably tolerable, but to use E15, richer main jets will certainly be needed.

Just some thoughts,

NTX5467

[buick man]

Hey.

Here is one good remedy for the off idle starve pause you speak of. For example here for your review is the enlarging of the idle channel restrictor. The lean out created by ethanol makes keeping things around 14.2 or hard to do without resorting these kind of tactics along with recurving your distributor.

Ethanol is very good solvent. Run it in your engine and you will be driving in time a 4-wheel lathe.

Fuel additives such as Sta-Bil, do not prevent the accumulation of water via the hydrophilic action of ethanol. It will retard the formations of deposits but not bacterial growth that you did not have with "real gas". It does help.

Leaded aviation gas is a good source if you are storing a car. It can and is design formulated to allow months of sitting without negligible degradation. Add Sta-Bil to this and your good to go.

But to get back to the free fall down hill trend of fuel in the U.S., and if we have to run on this crap, we will have to deal with issues such as spark, spark advance, and fuel to air ratios if we keep the carbs. We may even be forced to go to aluminum manifolds with electronic fuel injection bungs, electronic fuel injectors, crank sensors with dedicated coil packs, main computer, fuel/air diagrams, pressure fuel line regulators and in-tank fuel pumps with return to tank fuel lines.

The photo below is showing the enlargement of the idle channel on an AFB Carter 2507S 4 bbl carb. The stumble that occurs upon acceleration after idle is due to the need for more fuel to air requirement. A rod is shown being inserted into the restrictor area for slight enlargement. The distributor is also recurved to accommodate the change over.

Edited July 20, 2011 by buick man (see edit history)

[Aaron65]

David, I'd personally like a little more info on that idle channel enlargement...my Skylark has an AFB and I'm in Ethanol country, like most of us.

[NTX5467]

There's also an adjustment on QuadraJet spread-bore carbs. If it has the plug right under the air horn gasket (where the air cleaner sits), drill a small hole so that an extractor can help you pull the plug out. Right under that is the power piston, with some sort of adjustment "knob" on top of it. I don't recall which way you turn it, but it affects off-idle transition and emissions. It also controls the "full down" stop for the metering rods in the jets. You'd want to raise the rods slightly, I suspect, which would probably be a clockwise turn . . . but not very much of one. When done, replace the plug and seal the hole if you drilled all the way through it.

In the S-A Designs book on Rochester Carburetors, there are also some circuits known as "adjustable part throttle" circuits. They started appearing in the earlier 1970s for emissions reasons, but they also take some of the metering consistency out of the carburetor. The book shows, quite graphically, where these circuits are in the 2bbls and QJets, plus how to deactivate them for better throttle response and such.

Regardin the cleaning properties of ethanol . . . it has been noted that on the earlier 4GCs and such with drilled fuel passages in the carb body which are "sealed" with a ball bearing, sealer, and then staked in place . . . with time, the sealer will deteriorate and let the ball bearing seal "leave", which causes a direct fuel leak on the top of the motor! Several engine fires from this issue, at weekend cruise events, have been observed over the past few years. So, IF you might smell gas under the hood, find out where it's coming from--NOW!

Just some thoughts,

NTX5467

[buick man]

Here's some links for bedtime reading:

Carburetor Tuning: The Air/Fuel Equation: Engine Builder

PickingCorrectCarb

[Guest Koala]

I have often wondered if it would help stop fuel vaporisation if the fuel system way modified to have a return line to the fuel tank as with the first generation pollution cars. This would entail fitting a Y fitting to the fuel line at the carburettor with a return line to tank, the return line has a restrictor so the carb gets the majority of fuel but there is a continuous flow of (cool ?) fuel cycling through the fuel lines even if the float needle is closed.

Fuel vaporisation likely occurs mostly between the pump and carb as it soaks up engine heat particularly when the engine is idling so if you can keep this fuel moving and replace it with cooler fuel from the tank then in theory the problem should go away. An electric pump and the bypass line to tank would be even better.

Just a thought.

Koala

[buick5563]

Interesting. My 63 Wildcat with factory air had a dual outlet fuel filter that returned to the tank. The primary (to carb) outlet was 5/16" with a smaller outlet back to tank. That would be something to try.

[Aaron65]

I made a fuel return like the one you described on my '53 Buick. Jon the Carbking told me about it on the phone one day...it helps out quite a bit. A little tweaking with float levels and jetting and I could probably get it to start right up hot on a hot day. I returned the line to the filler neck rather than drop the tank.

[old-tank]

Just a few more questions and observations...

"May contain up to 10% Ethanol" (or something like that)...but how much is it? Is it the ethanol or is the basic gas too volatile? For many years winterized gas (before ethanol) behaved similarly if used on hot days.

Last year, my 97 Ford F150 displayed a check engine light. Scan revealed lean both banks, a small vacuum leak was found and corrected --- no joy; an additive (BG 44K) was tried --- no joy. An Internet search showed an instance where excess ethanol in the gas could cause this. I did an empirical test on the fuel in the truck and compared to some stored gas and it seemed that the truck had about 30% ethanol. By now it was nearly empty, and after refueling has been OK.

During a recent 2 week period I filled my 55 about 20 times:

vapor lock=I anticipated and activated the electric pump before it could happen

carb boiling=not every time...maybe after 3 lunch stops

hesitation=not always

pinging=at least 3 tanks (and these tanks gave the best mileage)

fuel gauge reading higher than actual=3 tanks (after 292 miles the gauge was reading 1/4 tank where I usually fill up and expected to put in 15-16 gallons...it took 19 gallons:eek:) does the fuel sender float ride higher in E-10?

fuel brands=BP and Citgo gave the best mileage and least side effects; Valero was the worst.

Willie

[NTX5467]

Actually, Koala, there are a good number of fuel filters and vapor separators which were used on early 1970s USA cars. Chrysler and GM especially. On GMs, they'd usually use a fuel pump with a return line from there, i.e., "3 line" = 1 pressure output, 1 input, 1 (smaller) return to tank. Not sure how Ford addressed that situation.

No real need to plumb with any brass fittings, just cut the line and put the filter/separator in line and add the line to the tank. Just need to find (or bend) a section of fuel line where the separator can be installed vertically.

In reality, though, all of the fuel return situations usually have a drilled restriction in them to force fuel to go to the carb rather than stay "in the loop" of the return line. A "shadetree" restriction could be a carb jet installed in a rubber hose for the fuel return line--just don't use one too big.

Thanks for the research information, Old-Tank! Quite interesting. Considering that the ethanol is usually "splash blended" with the base gasoline stock, errors in concentration can occur.

Just some thoughts,

NTX5467