Fuel Pump?

[Tommy E]

How do I test a mechacal fuel pump in a 77 dump truck

Topic

[619DioFan]

Gas or diesel ?

[Tommy E]

its gas

[college man]

you would have to hook up a mechanical fuel tester gauge
somewhere in the fuel line. what make and engine is this?

[Thomas]

What’s the problems you’re having? think it’s not pumping gas at all? or just pumping to slow to keep the motor running?

If you think it’s not pumping at all, I’d just pull the line off the carb, and stick it in a bottle, then run the motor off gas poured in the carb and see if any gas pumps into the bottle.
The pressure for a carbed engine is pretty low, so if you get a fuel gauge hooked to it, I believe it’d only read a couple pounds pressure.

[Bill]

Since we can’t seem to get the Year/Make/and Model of the truck it must be TOP secret. I didn’t know that the Pentagon had a secret dump truck.

Anyway….a healthy fuel pump on a carburetted HD truck should have around 3.5 to 4.5 lbs. pressure. It should pump about 1 pint of fuel in 30 seconds and should have at least 2 in. of vacuum on the inlet side.

That is a general rule of thumb for any truck built in North America.

You would need a pressure/vacuum gauge to test it.

[EricTheCarGuy]

More info would be nice. Is it carbureted? If so, I would look there if you have a fuel delivery issue. You’re more likely to have a problem with a carburetor than a fuel pump. Any additional info you could give us on the problem you’re having would be helpful.

[Author]

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