Fuel Pump Question

[notahybrid]

Hey, I have a 68 c10 w/ a 250. I am having a problem that I think may be due to hte fuel pump. When you take the fuel line off the carb, should there be a steady stream of fuel comming out with the engine running? Mine currently is pulsating and I think is starving the carb. Thanks

[Longhorn Man]

that's how it is supposed to work.

[GREASEMONKEY72]

Originally Posted by Longhorn Man

that's how it is supposed to work.

you sure? cuase ive always seen a stream rather then pulses

[Ironhead]

If you run a line into a container such as an quart oil bottle, crank the engine over without starting. At a minimum a stock pump should pump about a pint of fuel in about 30 seconds or less. If you get less than a pint in 30 seconds, look for a restriction in the line such as dent or kinked line, pinched hose, or clogged fuel filter. Reconnect the fuel lines and perform a pressure test by installing a gauge near the carb and start the engine... should show 4 1/2 - 6 pounds of pressure for a 250. Stop the engine and note if the pressure... should drop off slowly... I pressure drops quickly, the outlet side of the pump may be leaking. If these checks are good and you feel the engine acts like it is starving for fuel, double check the ignition system. Good luck...

[GREASEMONKEY72]

dont forget to check the lines for cracks and splits

[Longhorn Man]

Originally Posted by GREASEMONKEY72

you sure? cuase ive always seen a stream rather then pulses

a mechanical pump will always work like that. An electric one will do a steady stream.

[GREASEMONKEY72]

Originally Posted by Longhorn Man

a mechanical pump will always work like that. An electric one will do a steady stream.

i know the electrics will but if i remember right the mechanical will put out atlest almost a steady stream not like major pulses is what i ment

[notahybrid]

I appreciate everyones help!

[68gmsee]

Pulses at low idle and may look like a stream at faster idling. That's how it works. A lever pushes against a diaphragm to create suction and pressure action...

Now, if you have a weak diaphragm, plugged sock in the fuel tank or restricted fuel lines (that's what my problem was) it will cause a weak stream.

Fuel pumps are cheap and easy to replace if you suspect it.