Expert: Brad Sears - 5/6/2011

Question
hello,

  I have a 67' mustang conv. It has a 289 4.7 engine in it. I just re did the head gaskets, water pump, new edlebrock performer intake manifold, 4-barrel edlebrock carburetor, t-stat,fuel pump, new fuel line all the way through, starter, solenoid, battery, voltage regulator, ignition switch, full tune up except the points and condensor. The timing is 6 degrees, the points are 25 degrees, the points are set to .017, the spark plugs are gapped at .35 and i have been running 87 octane in it. the seals on the valves were also changed to run non leaded gas. the problem i am having is when the car is warmed up and i shut it off from 2 mins. to 1 hour or so the car has a problem starting. It turns over for a good 5-8 seconds before it will start. (always starts ) i am stumped at the moment, maybe you could shed some light on this for me. that you for you time  

Jeff

Answer
I rebuild old car carburetors for a living and have never been a fan of the Edlebrock (old Carter 4 barrel carburetors). It sounds like either one or two different possibilities. First the float bowl is siphoning out on shut down, what we used to call peculating. You can check this when the engine is hot buy removing the air filter when the engine is running. Then looking down the carburetor bore using a flash light have some one shut the engine off. Watch for fuel continuing to dribble out of the main discharge nozzle into the carburetor bore. This can some times be cured by lowering the float level by about 1/16th of an inch. The second is to make sure that you have a phenolic (plastic type) spacer insulating block between the carburetor and the intake manifold. It is possible that the heat from the engine is transferring up through the intake into the carburetor base and boiling the fuel in the float bowl. After an hour or so the automatic choke will begin to set and help the car start. But before an hour the choke is open. Before lowering the float remove and read the color of the spark plugs They should be a nice light tan color. If they are almost bone white the engine is running lean and if they are black the engine is running rich. If they are white do not lower the float.