Fuel

Anything Corvair related
User avatar
bbodie52
Corvair of the Month
Corvair of the Month
Posts: 11872
Joined: Mon Aug 06, 2012 12:33 pm
Location: Lake Chatuge Hayesville, NC
Contact:

Re: Fuel

Post by bbodie52 »

Vapor lock — if it occurs — only refers to a condition where the liquid gasoline has been heated to the point where it boils and converts to a vapor (preventing liquid gasoline from being delivered in a state that can mix with air to fuel the power stroke of the internal combustion engine). This can occur in the steel feed line between the gas tank and the fuel pump (at a point in the line where heat is being transferred to the fuel), or it can occur inside the carburetor body, if sufficient heat is transferred from the engine to the metal carburetor body. It would not prevent the engine from cranking when the starter is engaged. If your engine won't turn over (crank) that would generally be caused by an electrical fault or a depleted battery. When your engine is cranking the mechanical fuel pump should be able to create a vacuum in the fuel feed line to draw gasoline from the tank to the mechanical fuel pump, where it is pressurized and delivered to the carburetor float bowls. (If fuel is present in the float bowl fuel reservoir in each carburetor, you should be able to hold the choke open and look down into the carburetor throat. Manually opening the throttle should cause each carburetor accelerator pump to force a visible jet of gasoline to squirt into the carburetor throat, which confirms the presence of fuel in the float bowl).

Vapor lock does not prevent the engine from turning when the starter is engaged.
wikipedia wrote:Vapor lock is a problem that mostly affects gasoline-fueled internal combustion engines. It occurs when the liquid fuel changes state from liquid to gas while still in the fuel delivery system. This disrupts the operation of the fuel pump, causing loss of feed pressure to the carburetor, resulting in transient loss of power or complete stalling. Restarting the engine from this state may be difficult.
:link: https://en.wikipedia.org/wiki/Vapor_lock
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
User avatar
terribleted
Posts: 4588
Joined: Sun Apr 18, 2010 2:36 pm
Location: Atlanta, GA
Contact:

Re: Fuel

Post by terribleted »

So you drained the fuel. How does the tank look inside?? Is it full of crud? How did the fuel sock on the sending unit look? Can you blow thru the sending unit pickup tube or is it blocked?? I am betting you did none of these things as you did not report anything useful except you removed what may be a perfectly fine electric fuel pump...not an action that would help find your trouble. I saw no report from you about whether or not there was any fuel flow at the carbs...this should have been your first test...I told the procedure above. WHY would you come here looking for advice when you do not seem to want to listen to those that have been there before?? The only way you can easily verify if the system is plugged with debris is to see if there is debris in the system. You may be able to remove and inspect the carb inlet filters to see if there is debris in them but seeing what the interior of the tank is like is the true test. You emptied the tank....now is the time to pull the fuel sending unit and see for real whether the tank is full of crud.

You say now the engine will not turn over. What exactly does it do? Does the starter click, grind or make noise? If not then electrical or starter issues are at hand. Are you absolutely sure there is enough battery charge to turn the engine over, try jumper cables from another operating car or booster charger installed while cranking perhaps. Try turning it over manually using a 3/4" wrench on the crank pulley. You may not be able to turn it by pulling on the belt. Be sure of course that it is in neutral. If it does not turn by wrench then you have an internal issue. After trying unsuccessfully to turn the engine over using the wrench remove all the sparkplugs and try again just to be sure one or more of the cylinders is not full of fuel causing a fluid lock. If the engine still will not turn with the wrench and no plugs installed then remove the engine, tear it down, and find out what broke.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia
TheCommish
Posts: 84
Joined: Fri Apr 22, 2016 5:49 pm
Contact:

Re: Fuel FIRE!

Post by TheCommish »

Now I did it! Pulled all plugs, turned it over, cought fire, wires, carb, etc, lucky I put it out in about 2 minutes.!
User avatar
terribleted
Posts: 4588
Joined: Sun Apr 18, 2010 2:36 pm
Location: Atlanta, GA
Contact:

Re: Fuel

Post by terribleted »

You pulled the plugs and turned it over with the 3/4" wrench and it caught fire? How? I said to remove plugs and turn over with wrench. Where did the fuel come from? Did it spurt out of a cylinder? If so the engine was likely hydro locked from one or more cylinders being filled with fuel. Sparkplugs removed with the ignition system live is not a good way to crank over the engine with the starter. You always disconnect the Ignition feed to the coil before doing things like this. This is some of the most basic mechanical knowledge there is (fuel and spark do not mix, and that spark plug wires and distributor caps will arc to anything metal nearby even across a fairly large gap when energized). I would suggest perhaps you need to find a mechanic to help you sort this stuff out before you hurt yourself?
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia
TheCommish
Posts: 84
Joined: Fri Apr 22, 2016 5:49 pm
Contact:

Re: Fuel

Post by TheCommish »

Update....
Hooked up electric fuel pump with new cartridge fuel filter. Tested the pump sends fuel properly. addressed Vapor lock. Pulled all spark plugs, to turn engine over to clear vapor lock. Hit starter, poof Fire in engine compartment! put it out, minor damage, forgot to disconnect coil wire. I am replacing right carb, and rubber this week. I have not attempted to start the car yet, and will with Fire Extingusher at hand. Any advice for this old man?
User avatar
toytron
Posts: 833
Joined: Mon Dec 28, 2015 4:30 am

Re: Fuel

Post by toytron »

It is a scary thing. I had a friend that worked at a shop that repaired gas tanks and radiators (whatever those are). Anyway he was pulling the fuel line off of a car on a lift and as the fuel ran down his arm and onto the floor the trouble light fell and the bulb broke and ignited the fuel all the way up his arm. He was fortunate that his boss was quick to notice and extinguished it before he was seriously hurt and any damage occurred.

Ed Stevenson


Edwin Stevenson
Industrial Electrician
Electronics Technician
65 corvair corsa convertible turbo
65 corvair monza
TheCommish
Posts: 84
Joined: Fri Apr 22, 2016 5:49 pm
Contact:

Re: Fuel

Post by TheCommish »

With new fuel filter on electric pump, now running 2 pumps, replaced right carb, and rubber vac lines, engine runs well, at least it did. Today drove 5 miles, stopped for 1 hr, started drove 7 miles, no big problem, but appeared to be starving for gas, got 1 gal of gas, drove 3 miles, finally quit, waited 15 minutes it started and got home just 3 miles, but struggled all the way home, what do you think? someone said the Coil.
66vairguy
Posts: 4531
Joined: Tue Dec 21, 2010 3:44 pm

Re: Fuel

Post by 66vairguy »

If the engine is "locked" pull the spark plugs and attempt to turn over BY HAND. If a carburetor has flooded a cylinder the fuel will be pushed out the spark plug hole - IGNITION OFF AND HAVE A FIRE EXTINGUISHER READY.

BTW. It has been reported a few times that engines started up on old gasoline can seize the valves in the guides, usually after the engine runs for 10 - 20 minutes. I hope this is not the case, that's why you must turn the engine by hand, NOT with the starter until you are sure the engine turns freely. Yes a starter can bend things!!!

Generally speaking fuel that sits for 6 months is considered questionable, even with a fuel stabilizer. Without a fuel stabilizer - one or two months is the suggested limit.
Post Reply

Return to “Corvair Talk”