kcarlasc

I have been having an issue strating the car after it gets warm. Starts right up in the morning, but after it gets warm and I turn it off and then restart its really hard to start, almost have to keep the pedal to the floor to get it going...

Timing and such is all great, done to specs from Lars. Thinking maybe vapor lock, no return hooked up... Once it starts runs fine...

pws69

What are the exact symptoms of "its really hard to start"?
- Turns over slow and groans?
- Turns over fast but doesn't fire?

SuperBuickGuy

check your float level - most hot-starting, fuel related problem come from the carb flooding the motor when it's hot. typically, one of the best signs is it's starting a lot easier (because it's richening the motor more than normal).

Also, you can turn the motor off (when hot), look down the carb and see if fuel is continuing to drip into the motor from the booster venturi



Here's a circuit - no idea what is on your car, but they all, basically, are the same - they draw fuel from the bowl into the motor, as there's no check valve, pressurizing the tank will cause fuel to come out of these venturis (or having too high a float level, or a sunk float)

johnt365

Try this too, next time you dive the car and get things warmed up, when you shut it down, pull the air cleaner and look down the carb. You are looking for fuel draining or dripping after the car is turned off.

The fuel gets hot, boils and drips out flooding the motor. (this would be if the starter spins fast/normal but no start.) If this happens, try holding down the throttle to clear the flood while you start.

kcarlasc

As I said.. pretty much have to keep the pedal to the floor.. like its not getting any fuel...sounds like what is mentioned below... but I dont see any fuel in the carb

kcarlasc

Fuel is definitly hot... run right next to heater hose on the intake, trying to move it away from there... and as you said.. when I hold down the throttle it starts...

kcarlasc

I should mention.. brand new Holly Ultra Street Avenger.. but had the same issue with the edelbrock that was on there....

johnt365

IF, the conditions are right you can sometimes actually hear fuel percolating in the bowl. Lowering the float level can help keep it from boiling over. That carb has external adjustments so you could experiment pretty easy. Also a heat insulator/shield may help.

gg521

You mentioned that your fuel line runs close to a heater line. The real issues is the heat from the intake manifold heating up your carb and perculating the fuel in the bowls. I race vintage and had this problem at one time. I run a little lower level of fuel in the bowls and have the extended vent but the solution to stop the boiling was insulating the carb from the manifold. However, try lowering the fuel level first to see if that works, as suggested by others.

SuperBuickGuy

the fuel is going out the tube, onto the butterflies, into the manifold and vaporizing..... thus making too rich a mixture because now the a/f ratio is wayyyy off... by putting the pedal to the floor you open up the butterflies and increase the amount of air in the plenum. That brings the a/f ratio to a condition where it can run.


the fact it's a holley makes me believe in my original advice even more - and it's soooo easy to lower the float level on a holley - IIRC a 9/16 box end and a screw driver.

here's a youtube on how-to
http://www.youtube.com/watch?v=ge-mIk6nEYQ

kcarlasc

Will give the float adjustment a try this weekend, also going to relocate the fuel line as well..

Thanks!!!

SuperBuickGuy

Old trick to find out whether or not it's too much heat in the fuel line - wrap the fuel line in aluminum foil. Shape the foil in a tear drop shape. And generally speaking it's the line going up the front of the motor that's the problem.

Also, if it is getting too hot, run a fuel pressure regulator off the back of the carb then back down the return fuel line. The least amount of time the fuel is in the line, the less chance you'll have for vapor lock/heat soak in the line.

Matt Gruber

hook up return and route lines away from heat. Use 4 hole heat isolater gasket carb base.
if it is still a problem a $3 fan and duct to cool air works for me 100%. i just switch it on when in doubt.
a carb appreciates a cool breeze!

7T1vette

You might also have an electrical problem in the starter system. If the main power feed wire and/or the frame-to-starter/engine ground cable are deteriorated or not making good contact, that could cause the same problem. Your starter solenoid could also be at fault. IMO, the only way the starter motor could cause such a problem is if the commutator brushes are worn out and making poor contact.

ktmdon

I had this problem years ago with my 73. The starter was overheated. Is your heat shield missing ?

hdpete98

To much initial spark advance is usually the problem.

7T1vette

That's another good possibility.

exposingtime

When was the last time you changed your battery? Might not have enough cranking amps.

worship79

Does it act like this when trying to warm start it? Looking to see if maybe we have the same problem.

kcarlasc

I never gave the starter a thought.... There is no heat shield so that could be it espicaliy since I had the same issue with the edelbrok carb.

Battery is a red top and is only about a year old and cranks well...