Help! Fuel System Troubleshooting

[60vete]

Car starts ok when hot and electric choke seems to be doing its job.

Eventhough I pump the accelerator many many times it won't start.

However,When I manually add about an ounce of fuel directly to the carb it starts right up. Sounds like the fuel delivery but how can I narrow it down to the exact cause?

I dont want to buy and install a new pump onlyfind that that is not the solution.

Bob

 

[cntrhub]

Sounds like you have no fuel going thru the jets in the carb. You throw a cup pull of shots down the runners and poof she lights.

So, I would eliminate spark being an issue because it fires the fuel like no problem. I would eliminate compression because it fires is #2. I would pull the carb off and dip it on carb clean and rebuild the unit.

Now, it could be a low fuel level so as the low circuits do not receive the level of fuel to be sorta, under the water table. That calls for a float level check. The point being, you can rebuild the carb and have your fuel problem nailed is did you check the fuel pump and the gas in the tank and all the obvious before you pop the carb off!!!

You may not need to go through all that trouble if you have no gas in the tank. So, you need to walk that fuel from tank to carb bowl.

You nail, "No-Starts" by remembering then walk your three causes of no start. You will have that puppy started in no time.

 

[2X4's 60]

Need more info. Is this a cold start problem only? After it has sat for a few days? After you manually add the gas, does it run fine? Once it fires, shut it off and try again. Does it fire right up? If so, the gas in the carb. is evaporating or leaking out while it sits. Very common.

 

[60vete]

OK you nailed the symptons exactly!! It is a cold start problem that occurs overnight. When I add fuel directly the first time I start it in the moring it fires right up. For the rest of the day it starts up/ shuts down/starts up and runs just fine.

You indicated it is common so what do you do to prevent/cure the evaporation? Although there is no obvious leakage, I am going to tighten down all the fuel line clamps Other than that any other suggestions?
Thanks

 

[wallyknoch]

Just a stab in the dark. Parked hot and allowed to cool off overnight can or may cause percolation of the fuel from the carbs fuel bowls. Thereby emptying them until the pump refill the carbs. A insulated gasket under the carbs may cure this problem 'if' this is your cause in fact....

 

[60vete]

That sounds like a reasonable possibility and relatively easy fix if the insulated gasket can be found.

CORVETTE central shows an insulated "spacer" but for a 62 300 hp I have a 60 283 4 bbl. so I guess I need to look around for one that fits my carb.