Fuel or electric?

Ricosan

Ricosan

Senior Member
Hey Guys,

Two days ago I finally got everything sorted with the engine as best I could without a timing marker. I drove to the nearest station with ethanol free gasoline. About 10 miles away. I topped off the tank and took the back roads back. The car drove and operated flawlessly.
I parked the car in the garage. When I went to start the car yesterday, it would barely try to start. The car has always been hard to start when cold. Choke didn’t help matters even though it acted like it was starving for gas. Now I can’t even get a a single explosion from the engine.
It always starts instantly when warm.
I checked the spark plugs to see if there was any fire. I held the wire to the stud nut and it produced a spark about 1/2”. Is that adequate? It is a Mallory 12V dual point distributor.

Ricosan
 
Just got back from the garage. I took the line to the carburetors off and attached a brass outlet to the fuel pump which I fed into an empty coke bottle I taped to the outlet side of the fuel pump. Turned the engine over but not a drop of fuel!
The sediment bowl is full.
I suspect the fuel pump. I am a bit surprised as I have less than 100 miles on this engine but this will be the third fuel pump!
I’ll check the line from the tank to the pump after lunch.
 
check valves--just a small amount of crud can keep these from working. turn engine over and see if any bubbling or swirling is occurring in the sediment bowl, indicating a bad check valve
 
An old flexible fuel line from the fuel line on the firewall to the fuel pump can swell closed due to alcohol in the fuel, or just old age. They can also put rubber crud in the fuel line which can restrict flow through the screen in the fuel pump, and or get under the little valves in the fuel pump, causing them to loose seal. In any case, you probably should have a filter somewhere in the fuel line.

Some of the gaskets on the glass bowl are prone to lose seal, causing the fuel pump to pump air instead of gas. Check that it is tight.
If you pull the fuel pump be sure to check the stroke of the fuel pump push rod. As you crank the engine, it should stroke about 0.2".
 
I've also had a problem with the sediment bowl gasket allowing air to be sucked in. Surprisingly, I have had trouble with the neoprene gaskets but not with cork gaskets. It seems it should be the other way around, but not in my experience. Check the sediment bowl rims for chips etc. while you have it off.
 
I have always made my own fuel bowl gaskets. Takes about 10 minutes to do with all the latest material available just about anywhere at Napas.
 
It seems like you are still dealing with the original problem. I had the rubber filler tube disintegrate on the inside and block the pipe in the tank. Strip your pump and see why it's not working. Syphon the gas from the tank into a clean container and check it out. Fit a filter!
 
Hey Guys,
Alan, will check for swirling in the sediment bowl tomorrow.
JT, I poured gas down the carb. It started to go but died as soon as the gas burned out.
Tubman, I have a cork gasket on the sediment bowl. I’ll check tomorrow to make sure it is tight.
69a, it does feel like I’m starting over.
Update: Today I pressurized the gas tank but got no fuel through the pump.
Richard
 
You had the same problem at the beginning of the year. "clogged pump". I think you are treating the symptom and not finding the actual cause.
Try disconnecting the fuel line at the firewall, before the pump, and see if you can syphon the gas from the tank.
 
Good morning,
69a, I disconnected the fuel line between the fuel pump and the carbs. I could get no fuel through the system via a pressurized gas tank.
As you suggest, I’ll take the line loose that comes from the gas tank to the inlet side of the fuel pump today. This should tell us if it’s the pump or the gas line that’s stopped up.

Tinker, I checked the compression about 2 weeks ago. All cylinders within 3lbs. I measured the vacuum last week. The vacuum read 15. Last week it was running purdy good.

Richard
 
Just got back from the garage. I took the fuel line loose from the end of the 12” rubber connector to the fuel pump. Put a coke bottle over the end and added a small amount of pressure. Gas flowed into the bottle.
So now we know that the line from the gas tank is open to the rubber hose attached to the fuel pump. I think that the rubber is (2 months) still good and was installed along with a rebuilt fuel pump.
The sediment bowl is full of gas. I can turn the engine over but it is not pumping the gas from the sediment bowl through to the carb side of the fuel pump.

Terry, this was my first time using a vac meter. I read somewhere in my research that the number would be lower than the ideal 20 when multiple carburetors were involved. I don’t know if 15 is a good or bad number.
Richard
 
In my case it was a pinhole air leak in the fuel line. Apparently it doesn't take much to lose the siphon/vacuum.

Good luck!
 
jrhaelig said:
In my case it was a pinhole air leak in the fuel line. Apparently it doesn't take much to lose the siphon/vacuum.

Good luck!
Click to expand...

I agree JR. Pressurizing the tank is not simulating what the pump is trying to do.

Get a couple of yards of clear plastic tube connected to the fuel line at the firewall and SIPHON the gas into a container. if you can't siphon or you get new air bubbles in the tubing you have a leak between tank and pump as JR suggested.

Now take your container with the gas in it and connect your tube to the inlet side of the fuel pump, have the container about the same height as the pump an see if it will transfer the fuel by cranking the engine.

Fuel in the glass bowl on the pump does not tell you anything. It will always be there unless you take it off and empty it.
 
I've just gone through a similar problem. I got some no corn gas. It was in a tank at the side of the little station. It was LOADED with crud. Had to have fuel pump and carb cleaned, (Charlie NY) dropped tank and flushed it out, etc., etc. I haven't cranked it since. Been working on my display engine project.
 
Ricosan, try this. Loosen the fuel pump bolts to manifold. Turn the engine over to see if the push rod will lift the fuel pump. At top dead centre of the fuel pump rod you can now manually push the fuel pump up and down by hand to work the pump by hand without the sound of the engine. If you can’t get any stroke at all your pump rod maybe worn enough to not activate the pump. Either way this will help to diagnose your problem. Also can you blow back from the flex hose to the gas tank( no blockage in the pickup) inside the gas tank?
 
If you aren't getting fuel out of the outlet of the fuel pump, then the pump isn't working for some reason. What engine are you running? The post that "danliveshere" posted would give you an indication if the pump is being actuated by the camshaft.
 
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