Marginal fuel pump issue

[WPVT]

Am I correct that a mechanical fuel pump could be become marginal to the extent that it would run an engine fine, but could not suck or pump gas at the speed of a starter motor ?

This is on a 1953 dodge flat head 6.   

[Guest]

YES.

[padgett]

and a Model A had to go up a steep hill sdrawkcab...

[W_Higgins]

36 minutes ago, padgett said:

and a Model A had to go up a steep hill sdrawkcab...

 

Maybe if you're headed to the moon.  I have yet to find a hill that my Model A would not ascend in a forward gear.  Having to go up a steep hill sdrawkcab is a tale typically attributed to Model T's that had the gas tank under the front seat (and not all T's do).

 

 

[Bhigdog]

1 hour ago, WPVT said:

Am I correct that a mechanical fuel pump could be become marginal to the extent that it would run an engine fine, but could not suck or pump gas at the speed of a starter motor ?

This is on a 1953 dodge flat head 6.   

 

I had an issue with my 57 Buick. Ran fine above 1000 rpm but would die under that. Turns out one of the fuel pump valves had come out of it's bore and was for all purposes  MIA. Reset and staked it in place and all was well..............Bob

[FLYER15015]

2 hours ago, WPVT said:

Am I correct that a mechanical fuel pump could be become marginal to the extent that it would run an engine fine, but could not suck or pump gas at the speed of a starter motor ?

This is on a 1953 dodge flat head 6.   

If you only drive the car on weekends or holidays, you have 2 choices.

1. Sit there and grind the starter till the battery is almost dead, and the starter is too hot to touch.

2. Put an electric pump AND a large clear filter back at the tank, flip the switch, wait a few seconds, and start her up.............

 

Ain't this new century grand ?

 

Mike in Colorado

[TerryB]

These guys probably have a kit for your pump   http://www.then-now-auto.com/fuel-pumps/

[padgett]

"  I have yet to find a hill that my Model A would not ascend in a forward gear. " couldbin a T, I guarantee nothing from memory. Part of the tissue was than my cars now are older than when Model T and As were still somewhat common and was a gearhead when postwar cars were newish. Know part of my attitude is from my years at GMI and with GM and the attitudes of those few who were likeminded.

 

Do find it interesting that some of the most prized parts today did not work when new and many were recalled.

[WPVT]

The sediment bowl is full of gas, not sediment. The pump works fine when the engine is running, but doesn't suck or push gas when the engine is being turned over by the starter. I disconnected the inlet and outlet lines and checked, so I know that no suction was being created at low rpm's.

Things are fine if there is leftover gas in the float bowl. Engine starts, runs fine. But if, perchance, the float bowl gets drained by someone trying unsuccessfully to start the engine for a period of time, then the pump doesn't have the strength to get gas back into the carburetor. No start, everything dry. 

Carb is fine, inlet needle etc. The problem is a pump that works OK at 1000 rpm, but not at 30 rpm. 

 

 

[W_Higgins]

Above somebody suggested Then and Now -- just send it to them if you're not of a mind to rebuild it yourself.  They are extremely reasonable.  They have done several for me and all have been wonderful.  I'm capable of installing a kit, but for no more than they charge I have better things to do with my time.  

 

(Edit to add): confirm that the cam or push rod or whatever you have driving the pump is making a full stroke.

Edited August 10, 2020 by W_Higgins (see edit history)

[JACK M]

Get an old oil can that squirts or an old catsup squeeze bottle and put some gas in it.

Keep it on a shelf near your car.

Most times all you have to  do is loosen a wing nut and dribble a bit of gas in the recess  and the car will fire.

If not, repeat .

I only takes a second to remove the air cleaner if you have to go that way.

This gives the engine a chance to get its juice's flowing while you either tighten the wing nut or replace the air cleaner and close the hood.

People want to drop the car in gear and go with least amount of hassle.

I kind of like to check the oil and don't mind doing a prime and other under the hood duties that we take for granted with the modern stuff.

If I choose this electric fuel pump band aid I would have to buy several and I do have time to take care of my stuff.

The latest theory is that the gas these days evaporates out of the float bowl almost over night.

Others say that the gas is syphoning back.

Not sure which is right but I've been priming carburetors for many decades and I don't use up starters trying to start an engine that only needs a bit of a prime.

[WPVT]

Jack M,

    That's good, pragmatic advice. A ketchup squeeze bottle was exactly what we used to get things going.  

     I'm going to rebuild the fuel pump in hopes that it will be able to deliver fuel to the carburetor after a few turns of the engine. 

      I'll let you know if that works.

      Meanwhile, we'll keep the ketchup bottle handy.

      Thanks. 

 

 

[Paul Dobbin]

Put a fuel filter in the gas line too.  Most electic fuel pumps pump to much gas.  Lots of us use a return gas line to the tank which keeps the fuel moving

and can eliminate vapor lock on these hot summer days.  Just put a T fitting in the line before the carb. and run the extra gas back to the tank.