Mechanics of a fuel pump

[Rodney Bullock]

I had been down to the garage trying to start the 41 Studebaker. I noticed that I had gas in the small bowl (filled to the top) however none was getting into the carb. I tried turning it over and over must of the morning:mad:with not luck. I sprayed some starter fluid and it would run for a couple of seconds and then die.

On the WA-1 carb there is a large screw on the fuel bowl where the filter is, I removed it and filled it with gas. The car start up and run nice until the gas was gone then it cut off.

I have noticed when I would drive the car that if I parked on a hill (nose up) the car would be very hard to start. On level ground it start very easy. I guess I have had this problem for some time.

I pull the pump off and sent it to antique cellar/ then and now. They are using this rubber for the insides that is resistant to modern fuel.

My question is the pump has One or two functions? Doesit pull fuel from the tank then push it up to the carb? Does it pull it up and just keep flowing it to the carb and the check ball stops it? If the bowl is full would that mean that it gets to the pump and stops? can it be tested with a hand held vacum tester?

[Don Coatney]

Rodney;

Fuel pump is two fold. It sucks and blows.

Is there any gas in the gas tank of your 41 Baker:confused:

[Jim Saraceno]

My question is the pump has One or two functions? Doesit pull fuel from the tank then push it up to the carb? Does it pull it up and just keep flowing it to the carb and the check ball stops it? If the bowl is full would that mean that it gets to the pump and stops? can it be tested with a hand held vacum tester?

Don is correct and as it pushes the gas up to the carb the float chamber will fill up and close the needle valve to keep the gas from overflowing the carb.

The best way to test a fuel pump is while it is still in the car....

First do a volume test. The pump should put out 5-6 ounces in 15 strokes.

If that is not good put a pressure/vacuum gauge between the pump and carb. It should read about 4 1/2 lbs.

Then put the pressure/vacuum gauge on the fuel pump inlet. You should get 6 inches.

[Rodney Bullock]

yes, gas in the tank. I have a spare pump here that I try it on. I did d an on car test. I unhooked the line from the carb and turned it over, nothing came out. Glass bowl was full.

[Plymouthy Adams]

the glass sediment bowl is for the "sediments" ie foriegn object to collect and allow to observe the said condition for deciding when it is time to clean the bowl..gas here does not mean there is fuel going in or out of the pump at this particular time nor does it guarantee there is fuel in the carb. You should at this time disconnect the inlet line to the pump and blow back through the lines into the tank...have some one standing by the open fill tube with gas cap off and listen for gurgling ..if possible at this time to inspect the inlet screen on the pump itself, do so, if dirty..stop and remove pump to clean so to possibily injestion of this small rusty contaminates that my cut your diaphram...reconnect the line to the fuel pump and disconnect the outlet line, turn engine over and see if you now have fuel flow..do you have an inline filter underneath the car or before the pump somewhere?

if blowing back to the tank gets fuel flow..then you are having problems with excess sediment in the tank, blocking the pickup or else if you have an inline filter that had become plugged on the input side or a combination of both..either condition should have you pulling the tank for a flush out..and replacement of the filter...if you don not have an inline filter..I do recommend you get one..

Edited December 15, 2009 by Tim Adams

[Robert Horne]

Had problem with no gas or not much gas going to carb with my 49. The problem was within the fuel tank. I took the tank off, strapped to a cement mixer. Put Purple Soapy cleaner, bolts, chains, and whatever in the tank, and turned on. Flushed out several times, came out very good. Final rinse with K1. Never had problem after that.

[Robert Horne]

My tank cleaner.

[greg g]

Clever Bob, very clever!!! Rodney if there is gas in the sediment bowl and gas was bing pumped, (yett o be determined) then the problem is within the carb. Might simply be a stuck needle in the inlet. If the ca has been sitting a while, it could be gunked up and not opening to admit gas to the carb. Are you getting ay gas frm the accelerator pump when you work the linkage???

Also you might want to pull the plugs and clean them or get some new ones. Also remember the sedimant bowl is basicaly sealed and doesn't aloow gas to evaporate so any thing in there will stay liquid long after the gas in the float bowl has evaporated.

With all the cars you have, I would think an auxiliary gas tank, and a electric fuel pump with some hoses and clamps and a booster pact to run it would be a good investment for you. Find a place that does lawn mower repairs and get something from and old garden tractor or similar that holds a gallon or more.

Gas from the tank on most cars will flow by gravity to the region of the pump, most mechanical pumps are equally strong on the pull ad push stroke. Electric pumps are built to push better than they pull. So electrics are usually found close to the source.

.

Edited December 15, 2009 by greg g

[Joe Flanagan]

Rodney, I double checked the spare pump I have and it is not dual action. It's the single inlet/single outlet type, which is similar to what you have. If you need any parts or need to see how anything goes together, let me know. The diaphragms in it look practically new.

[Rodney Bullock]

My tank was repaired by RE-Nuz-It it is garunteed for life. I don't think it's a tank problem nor is it a cxarb problem because after I put fuel in the filter housing the car starts and runs very good. after the gas runs out it cuts off.

I sent the fuel pump to antique cellar they have done 3 pumps for me in the past.

The 41 is not my Holiday car anyway, I do my Ho ho ho ing in the usa with my chevolet

[Plymouthy Adams]

lets just hope you are not in a state of denial...what's it take to be sure the line and pick up is unobstructed..a many folks have had their re-done tank do just this very thing...

[randroid]

Rodney,

Early in the post you mentioned that when you park on a slight incline you have difficulty restarting the car, and while the excellent suggestions by forum members include (if not directly address) a possible cause and fix for this I had that problem and the culprit wasn't fuel pump, gas tank, or lines. It was the guy behind the wheel.

I'd rebuilt the B&B carb and it ran the engine like a champ but unless the car ('48 P-15) was parked level I had to crank it way too long to make either me or my starter very happy. I even went so far as to try to find an in-line check valve for the fuel line, and when discussing it with a friend (a competent mechanic who had a sign in his shop that read:

"Poor judgment on your part does not create an emergency on my part"

He started laughing and told me that if the check valve already in the system didn't stop the back-flow I'd be better off fixing it rather than making the situation more complicated without fixing it.

Those innocuous ball bearings we're supposed to drop into the carb before we put it back together are check valves, and I didn't have one in correctly. Darned if Roger wasn't right, but his heart stopped one day in his 53rd year and I was never able to tell him he was correct.

If you have had the top off the carb, peek at the balls (nobody go there!) and see if they look okay. Just a thought but one of those rare situations which stymies even the good guys.

-Randy