Death of a fuel pump ??

[Guest]

Im having some problems lately with my car not running well. It acts as if it wants to cut off after starting.......once I do get it rolling it may cut off when I come to a stop. Then its all I can do to keep it running (usually pressing the gas with other foot on the brake as I put it in drive) Oddly enough.........when going at highway speeds it will do fine.........then 10 minutes later as I near my house it cuts off. Ive taken my carb top off and cleaned and inspected everything I can.........checked the filter screen going into the carb........run carb cleaner through it..........and there was only a small amount of junk in it......next to nothing really. As I do more it seems to get worse.........I took it out today and didnt think I would make it home........it just acts like it doesnt get any steady gas at low speeds or at idle.........is my fuel pump dying??? I know it seems stupid to ask.......but it was put on new.......and then the car sat for a looooooong time before I got it..."GULP" 23 years. The carb was rebuilt when I got the car and Ive never had any problems with it. I just wanted somones opinion before I shell out 90 bucks. Im going to run a test tommorow to see how much its pumping.........but I should get one anyway right ???

[byersmtrco]

RE: Death of a fuel pump ??

Don't even bother testing it !!

[KULTULZ]

RE: Death of a fuel pump ??

Are you sure the idle mixture setting is correct and the idle speed/dashpot is set correctly? It may help to remove the idle adjusting screws and with an aerosol carb cleaner shoot solvent through the passages. Then rebalance the carburetor.

A bad power valve may be overly enrichening the mixture. Any signs of black smoke or excessive fuel useage? Choke linkage clean and adjusted correctly?

If it operates at speed, it is doubtful the pump is bad.

[JohnG]

RE: Death of a fuel pump ??

If you look at some posts from a month or so ago, I went through some fuel pump problems, only it turned out the culprit was a little-known screen in the gas tank. I was blaming the pump but eventually had to blow the crap out of it to get any gas. I have had no problems since then.

The moral might be that, given that these are all old cars and probably sat at one point or another, we need to look at the ENTIRE fuel system before blaming any one component. This means begin at the rear and clean the screen in the tank (blow it out). Then make sure your fuel line to the pump is not clogged. Then see if the screen in the carb is clean. Then see if your needle valve in your float bowel functions correctly. When all of those things are in proper condition, you can decide if your fuel pump is doing its job.

You may not check all those things but the main point is that there are a number of places for things to go wrong besides the pump. I put a brand new pump on and still ended up walking!

Following another topic, having an electric pump around for testing and backup helps out here.

IF your pump is bad, you have three options: buy another one, rebuild yours, or send it out to be rebuilt.

If you have the secondary pump on it for vacuum for the wipers, its a chance to improve that system as well.

John
58 Hardtop

[Guest]

RE: Death of a fuel pump ??

JohnG.........I checked the screen in the carb and there was nothing.........but I didnt know there was a screen in the fuel tank. All my troubles really began after I let the fuel gauge drop to empty........something I try to avoid. I figured I picked up some trash and would drive the car until it all came out (something Ive done before). This time is different.......and didnt know if these fuel pumps die slowly......or just give out all at once. Its just strange to me how I can go 70 with no problems.........then having to pump the pedal just to keep it alive at a stop light. Im gonna do as you suggested and see what happends. I dont mind spending the money to make my bird run like a top...........It just drives me crazy when I dont know exactly what the problem is.

[Alexander]

RE: Death of a fuel pump ??

If this problem only exists when the engine is hot and the outside temperature is hot, you may be experiencing vapor lock. The feul is boiling before it reaches the carburetor.

Gas is no longer formulated for carbureted cars. Our fuel pressure is only about 7 psi. Fuel injected cars have much higher fuel pressure (30 to 80psi), so the fuel does not boil.

Alexander
1959 Hardtop
1960 Golde Top

[Guest]

RE: Death of a fuel pump ??

Im having problems from the moment I turn the key.......it just wants to die out. After 4 or 5 tries........it will start but idle poorly. I rev it up and it does fine with no misses........then dies back down....sometimes cutting off. In "drive" it idles so low the gen light comes on.........but when I accelerate it picks up.

I had a 63 Comet once that vapor-locked a few times but this isnt like that at all. This weekend Im going to find out once and for all.........AHHHHHHHHHHHHH !!!! I still have a feeling its the fuel pump. I remember when I took the top of the carb off the main bowl didnt have that much gas in it........about half of what the back bowl had in it........and the floats were fine.

[JohnG]

RE: Death of a fuel pump ??

I have a see-through fuel filter between the pump and carb. While I didn't pick it to be see-through on purpose, it was helpful when I was trying to decide if I was not getting much gas.

The fact your car funs fine at 70 mph, however, makes it hard to blame the pump. But if you want to eliminate that, purchase a low volume, electic pump and substitute it. If the car runs the same, that was not it, of course. The electric pump is good to have around as a backup and can also pump other things. I think they are $40 or thereabouts.

The screen in the gas tank - there is a post from this spring where a guy cut an old tank up and had a picture. Mine was clogged. I drained the tank, removed the gas line and used carb cleaner and compressed air in the gas line fitting to get the crap out. Have had 1000 trouble free miles since then. Not a long job but cheap insurance.

[Guest]

RE: Death of a fuel pump ??

I really dont believe it.........it seems my needle valve (the one that dangles from the front float) was slightly coated with "something". This was causing it to stick.......therefore not enough gas was getting in the bowl. I cleaned both.......no problems. That little rubber tip was the culprit. I had taken it out long enough for it to dry........and noticed a white almost scaly looking film on it..........you couldnt see it when it was wet. I guess this will be part of my regular maintenance now........and it doesnt take but 20 minutes. I thank everyone for their help !!!!!!

[JohnG]

RE: Death of a fuel pump ??

Jeez... I was hoping for a little more exciting conclusion than that! Like maybe a sweatshirt in the gas tank or something unique...

Seriously, great job tracking down the details!!! Enjoy your ride now!


John;-)

[Guest]

RE: Death of a fuel pump ??

Ok.......the truth is.........they found Jimmy Hoffa in my gas tank.........well preserved I must say........and how they squeezed him through the little hole is beyond me ! :+