454 engine trouble staring

[realpank]

I have 1987 325 MH.

After sitting for a while it will not start up without putting gas in the carb. Motor turns over fine and runs great. Just does not seem to get fuel after sitting.
It will start up at the end of a weekend or one week camping trip.

Just a bother to start it this way and I know it is not particularly good for the motor.

Filters good, fuel lines are leak free.

Any suggestions welcome, thanks in advance for your help.
Chris

[gunner]

Should have electric fuel pump that should provide fuel to the carburetor when the key is turned on. Check the fuel pump to make sure it is pumping fuel, might have to disconnect fuel line to check. My 1984 the pump would run but not pump fuel, replaced and everything was fine.

[ROBERT CROSS]

It could be your losing "rest pressure" in the system, ck valve on the fuel pump may be bad....weak grey cells tell me it should be on the outlet nipple.(been awhile)😂
Carb bowl leak possible, but you would notice smell or see it.

Bob
🇺🇸

[davejay]

Hey,
A couple of things to look for. 1 your aux fuel pump by tank. Turn the key, it should fire up and hum. No hum, tàp it with the end of a screwdriver, sometimes they get sticky from sitting.
2 old gas .
3 carb is original? If so there is a rubber insert on the jets. These things went bad, and fuel would drain off the bowl. Made for hard starts. . Rebuild or replace carb. Go edlelbrock or fuel injection. Quad rakers were pretty old technology.
4 upon starting unit, spray some starting fluid down carb. If it fires right up or acts like it wants to go, it's not anything electrical, it's fuel related. My bet, aux fuel pump is acting up, and maybe your engine fuel pump is dying. The aux pump is to get fuel to the engine pump. If it is, but the engine pump is dead, you still won t start. That could very well be the problem. The aux pump will eventually get fuel to the carb, it'll bypass the engine pump. But that could take a couple of minutes. Hope this helps DJ

[suncoasteng]

You probably have GM big block with carburetor. If so, the gas is simply evaporating from the carb. You need to start the vehicle EVERY WEEK. And NEVER, EVER pump the gas pedal before starting. T

These older carbs had accelerator pumps, which also go dry. If you pump the throttle, the accel pump chamber is dry and you will just abrade the rubber seal. There are two ways to start these older engines. Either throw some fuel down the throat of the carb, or crank it for 10 seconds, wait, crank again for 10 seconds and continue to repeat til she wants to fire. Then, and only then, can you pump the gas pedal

[realpank]

Thanks everyone for the responses,

All very common sense.

I think it is mostly from sitting and evaporation. It does start and run very well once it has started.

Cheers to all,
Chris