My fuel pump starts right up, as soon as the key is turned. No issues with how well it does it's job. However, at random times, it will start pumping loudly. It actually sounds like some kind of engine knock. Sometimes, a blip of the pedal will shut it down. Other times. it runs and clatters until it want to shut down. I see no leaks and the engine doesn't flood.

Any ideas?

 

Is this for a injected engine or carb?

 

Do you have a fuel pump controller by chance?

carb or efi?

 

Yes, more info might actually help. Stock 239 flatty with one carb. Electrics have been converted to 12 volt.

 

Mine makes noise like that when it's pumping against an empty pipe (or one filled with vapor).

 

Deadhead system or do you have a return line? If you do not have a return line you may want to add one if the pump is straining.

 

It doesn't appear to be straining. Initial start up is as expected. The pump chatters until it gets the proper pressure, then stops.
The louder, noisier banging can come at any time. Within a minute or so of starting, or after I have been out for a drive. So far, it has only happened at idle.
It is a straight system, no return line.

 

What pump do you have (part number will be better).

No doubt a return system will cure this. Sounds like the pump is flowing more than what is being consume. Thus the pump is pumping against it self, building pressure. I've seen this type of occurrences twice in my short life.

 

Did the pump come with an inlet filter attached? Mine did and after a couple years I discovered the filter was disintegrating from the vibration of the pump. I mounted a new filter with rubber hose to isolate it. Pieces of the filter media could cause the pump check valves to hang open and run wild.

 

That's a product feature. It lets you know that the pump is running. But seriously, make and model# of pump?

 

I believe this is the pump. I'm not certain and I can't get under the truck today to verify. However, the price and look are relative. As is the pressure rating.

 

Forget something?

 

Oh, I suppose you want a picture too?

 

That looks to be a rather cheap pump...I don't think that I would buy another given your issues with this one. I have always had good luck with Holley "red" pumps and always mount them as close to the tank as possible. These pumps are much better pushers than pullers.

 

Wow that is so cheap I would keep two spares in the glove box! Summit sells external pumps as well, I think they were around $75 or cheaper but need to be regulated down and I would add a return line.
Myself I would not trust a $20 pump to get me home.