[markeb01]

I've been doing Google searches on this topic today and there are numerous related threads. The hard start problem is very common with the aluminum Edelbrocks regardless of car/engine brand, and worse with the manual choke 1405 model.

The solution consensus seems to be:

1. Fuel is boiling away in the float bowls since the manifold heat easily soaks into this area. Best fix is adding a heat isolator spacer under the carb, and if that's not enough also block off the crossover passages in the intake manifold, and check to make sure the heat riser isn't stuck closed.

2. Fuel may be evaporting from the float bowls. In reading the Edelbrock 1405 manual, the externally adjustable fuel bowl vent seems to have been eliminated. I haven't been able to confirm, but the bowl vent may be open all the time contributing to evaporation of fuel in the bowls, particularly when the vehicle isn't driven for extended periods.

3. There's an internal leak in the carburetor draining fuel into the engine. (I've had mine apart several times and never found any cracks evident).

4. The check valve in the fuel pump may be tired, allowing fuel to drain back into the tank, requiring more time to refill the bowls and the line leading to the carb. The easiest solution seems to be adding an electric pump near the tank, but for a variety of reasons this may not be desirable. The idea of a one way check valve in the fuel line gets discussed, but nobody seems to identify a compatible valve. The only check valves I have found are designed for 65 psi factory pumps, which probably wouldn't be suitable for a manual 5-6 psi pump.

5. There could be crud in the carb needles preventing them from sealing completely. (I've changed mine several times and the problem has never diminished).

6. I researched putting an electric auxiliary fuel tank cut off switch on the input line connected to the cold side of the ignition switch, but for the cost of the switch a person might as well change to a different brand of carburetor.

Bottom line, I'm no closer to an answer than I was yesterday. On my engine the crossover ports are already blocked and I have no heat riser. I will go ahead and install a 1/2" heat spacer I already have, but I'm convinced it won't help with hard starts after several days of inactivity. If I start the engine once and get it running, even if it never gets up to operating temperature, it will restart immediately any time during the day - so boiling gas in the bowls can't be the problem.

If anyone has other suggestions there's an enthusiastic audience waiting.