I have a 68 camaro with a 421 stroker motor. (SBC 400 block)

the car has an MSD 6AL box, msd billet distributor, msd wires, etc.

edelbrock 1406 carb, holly street dominator intake and seemingly stock 400 heads.


The problem im having is that if i go out to the car when the engine is cold and hasnt been run, it starts up with less than a second of cranking and runs fine.

However, if i turn the car off and try to start it again (example, stopping at the gas station) the car cranks very strong but will not start.

Sometimes, when this problem occurs, the engine will intermittently have a quick fire as if it wants to start but never actually does. (crank...fire...crank...fire... but no start)

Im stumped as to what the problem could be...

I have an inline fuel pressure regulator installed at 4.5psi and have tried it at 4psi and 5psi settings with no change.

I have a phenolic 1 inch spacer installed with insulating gaskets above and below it.

The battery has 770 cold cranking amps and 925 at 32 degrees.

since the car still cranks perfectly fine when warm, that would lead me to believe that the starter is fine.

Any ideas here guys, its incredibly embarrassing and i cant enjoy my car.

thanks

mike

 

Couple things come to mind. First is the carb; is it fairly new and no sign of float needle allowing fuel to weep into the engine? If the needle or seat is worn it will start great cold, but fuel leaking into the engine when warm will cause it to flood and not start.
Couple things you can do to see what's up. Get it warmed up, then pull the air cleaner and look inside the carb to see if you can see fuel seeping in. Or if you have a fuel gauge you can shut the engine off and w3atch the pressure to see if it drops.
The other thing I'd check is timing. Timing can easily cause warm/cold starting issues.

 

it could be boiling over. my 68 had that problem you might have to put a heat insulater between the carb and intake.

 

i have a 1 inch phenolic spacer and thick insulating gaskets above and below it.

 

when i shut the car down and look in the carb i dont see it weeping out of the squirters or anything but there is a thick white vapor that slowly rises from the carb, and if i pump the throttle by hand with the car off after running and look, there's even more vapor that comes out.

I have a phenolic 1 inch carb spacer installed with thick insulating gaskets above and below it.

the fuel line to the mechanical pump is metal but wrapped in a thick transmission line rubber hose that i split down the middle to wrap it around.

from the pump to the inline glass fuel filter is un-insulated metal fuel line, and follows tightly to the block to the left of the water pump.

from the inline glass fuel filter to the fuel pressure regulator on the intake manifold is un-insulated metal fuel line, with the regulator set to 4.5psi.

from the regulator to the carb is rubber fuel line, with enough slack to keep it off of the valve cover and other surfaces, its just "floating" in the air.

The carburetor is a brand new edelbrock 1406, which replaced an older 1406.

I set the float level to the correct specifications on my old 1406 but had the same problem. on the new carb i have no set the float level yet, but the carb is supposed to be dialed in "close" for a typical street/strip build.

 

Make sure the choke is open all the way when the engine is hot. If it's closed, that can cause hard hot engine restarts. And, you are giving the gas pedal a pump or two when you start, hot or cold?
I see a couple issues with your fuel line/hose routing, but that's not causing your starting problem.
Your connection from the steel line on the frame to the fuel pump needs to be rubber. It has to flex with the engine movement, a steel line could eventually fatigue. From the pump on, all the lines should be steel. I know guys like to run rubber fuel hose to the carb because it's easier, but it's not as safe.
I don't like using the glass fuel filters. Yeah they look slick, but glass can break.