I can't get my small black to start when it's cold without cranking for over 30 seconds. If I use a shot of starting fluid it starts right up. Any suggestions?

 

Welcome to the forum. Some additional information would help.

How is the car used? How many days between starts? Is it started every day? Does the choke operate properly? How do the spark plugs look?

Once it starts, and warms up, does it start again without problems?

Has the carburator been rebuilt recently? When is the last time the carb was rebuilt? Was the car in storage for a long time?

You might get some additional information from the FAQ site below:

http://www.corvettefaq.com/listing.asp?group=1&sub=9


Also, a search of the Forum Archives might help.

 

Yeah there is alot more information you could give to help us out.

General thoughts that hit me right away are:
Not a hot enough spark?
Fuel pump flaky?
Hows it sound turning over - not turning too good?
Choke?

 

ml -
There are 3 major causes for the problem you describe:

1. Oxygenated fuel. In most parts of the country, alcohol is being added to the fuel. Alcohol has a higher vapor pressure than gasoline, and it will evaporate quicker in a vented float bowl like the one on your '68. If you have ethanol in your gasoline, you may be out of luck.... buy stock in a starter company.

2. Bad fuel pump. If the checkvalve in your fuel pump is slightly leaky (internal leak - not visible from the outside), the pump will allow the standing fuel in the line between the pump and the carb to leak back through the pump and back to the tank. As the column of fuel leaks back through the pump, it will actually siphon the fuel out of the carb float bowl. To eliminate this problem, you can do two things: First, change your fuel pump out with a good new pump. Then, install a "checkvalve" filter in your Q-Jet inlet and make sure your filter spring is correctly installed to make the checkvalve filter work.

3. Sometimes (not as often as people will have you believe), the primary well plugs on a Q-Jet can start to leak. This will drain the float bowl overnight. To check, unbolt your carb after the car has been sitting for an hour. Simply lift the carb straight up and use a mirror to look under the primary side of the carb: You can see the primary well plugs from the bottom. If they're wet with fuel, you need to plug them. See my "Q-Jet Problems I have Seen" tech paper on how to fix this correctly.

4. Finally, and I add this as a 4th item, make sure your choke is operating correctly. Your '68 has a "divorced choke" system, and these go weak over time. When the engine is cold in the morning, tapping the gas pedal once should make the choke go completely closed. If the choke blade does not close completely over the airhorn, you need to do some choke work.

Good luck. Tag me back if you need assistance.


[Modified by lars, 10:08 PM 11/23/2003]


[Modified by lars, 10:09 PM 11/23/2003]


[Modified by lars, 10:10 PM 11/23/2003]

 

Thanks for the excellent information. I have only owned the car since August and have no experience with small blocks

One interesting thing. After driving the car and parking it in my garage I get the smell of gas. I have looked but found no leaks anywhere. Could this have something to do with the fuel pump and be a symptom of the starting problem?

 

ml -
If your carb is dripping out of the main well plugs, you can get a fuel smell after shutdown from the fuel dripping down into the hot intake manifold and vaporizing. Normally, this smell will be contained by the air cleaner, but an open free-flowing filter can allow the fuel smell to escape. If this is what is happening then the fuel smell is, indeed, related to the starting issues. So just unbolt the 4 bolts on the carb, unhook your choke rod, and lift the carb straight up far enough to get a mirror under it to inspect the primary well plugs. If you need help sealing it up you can send the carb out to me and I can install threaded-in well plugs for you to fix the problem.


[Modified by lars, 12:48 PM 11/24/2003]

 

your choke is screwed-up and maybe your carb is filthy. Clean and set the choke and you should be rocking

 

Does anyone know what number or year they used check-valve fuel filters?
Thanks
Terry