'78 c10 305 Hard to start after setting all night

[chasmotech]

Just bought last week. Prev owner said recent carb and fuel pump change.. After setting for 1 day it takes about 20 or so pumps and around 30 seconds to start.. Runs and starts fine after that. No fuel leaks or smells present. Seems like the carb bowl is dry and has to be full first? Anybody with same similar problems that may no a fix would be much appreciated. Thanks...
BTW... it is an OEM 2bbl carb...

[Stewart G Griffin]

Could be a choke issue;  Can you post a picture?


i also have the rochester 2bbl, but i swapped mine in with a different engine.   When you say OEM, did it come with the truck originally?

[Irish_Alley]

Does it have a. Clear fuel gauge on it. Also what it you pump the pedal a couple times how does it start right up.

[VileZambonie]

Check to see if the well plugs are leaking. Do you get a poof of black smoke when it starts?

[chasmotech]

Thanks... I will post a picture when I get a chance.. By OEM I think it is the same replacement as the original. I do have to pump it about 20 or so times before it begins to start.. I did notice a Puff of smoke when it started on several occasions.. I will first check the well plugs like you recommend. (Got to study up on carb's again. Last one I had was on a '41 plymouth mayflower..) All TBI or FI since....Thanks again for all replies.

[jaredts]

Vile might have nailed this, but...the 20 pumps part screams out accelerator pump.  Sitting overnight and having an empty fuel bowl the next day would be well plugs.  I would recommend letting it start and run for a minute and then shut it off.  Then quickly turn the throttle linkage while looking down into the carb. to see if it squirts out fuel.  If the fuel bowl really is emptying for some reason, you would be better off not to pump it 20 times.  You would have much better luck cranking it for ten seconds with no pumps, then pump twice, then it should start right up.  By pumping constantly like that you're not getting enough fuel in to start, but just enough to prolong filling the fuel bowl back up.

[78 Chevyrado]

Last 3 times that happened to me, it was a problem in the fuel pump;  it was letting the gas go back to the tank and it sucked the carb bowl dry.  I had that happen 3 times and switched brands and no more problems.  I used to have to pour some gas down the hole so i didnt wear the crap outa the starter.   I think the diaphram rotted or got a hole in it or something.

[chasmotech]

Thanks for all the advise and replies, It may take me a few days to get to it, but sounds like it is down to either well plugs or fuel pump.
also I will try the starting without pumping, like recommended till I can get it fixed..

[jaredts]

I didn't think it was possible for a bad fuel pump to siphon gas from the carburetor.  Maybe I'm wrong on that but doesn't the needle valve in the carb. sit above the float level so there's an air gap?  Like holding a water hose above a bucket--you can't siphon if its above the liquid?

[VileZambonie]

Like a toilet bowl tank... The fuel feed can't suck it back out of the bowl. When you start all you should have to do is depress and hold the pedal 1/3-1/2 way and crank the engine. when it starts pull your foot off the pedal and it should idle on the fast idle cam until the choke opens. If it doesn't start that easy and the fuel bowl is draining I would definitely suggest pulling the carb and checking those well plugs. JB weld (although it takes about 24 hours before you can put the carb back on) or some fast set epoxy will seal them back up.