Hard to start when stopped

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petecla

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After my Duster runs for awhile and I stop at the gas station. I have a hard time stating, I have to hold the pedal to the floor. How do I keep this from happening.

I have a std bore 318 with 360 heads mild cam and 650 edlebrock.
This also happened with a 600 edlebrock.
 
How close is the fuel line to somethin really hot? Could be tryin to vapor lock. Get a bunch of clothespins and clamp um on the fuel line all together in a row....maybe 6, 8...10 ...however many you can get bunched up. Might have to do it in more than one spot. This will absorb some of the heat from the fuel line. If the car starts after you do that, then you know the fuel line is heating up and getting the fuel too hot. You will need to reroute it accordingly.
 
You've got heat soak-induced percolation. Check your fuel pressure and make sure it is not higher than necessary. Insulate the fuel line from the pump to the carburetor by slitting 3/8" diameter fuel line hose and pushing it over the metal line, securing it at intervals with hose clamps. Undo any metal clips that hold this line to the engine, and find an alternate, non-heat-transferring way to hold the line in place. Make sure you've got a nice, thick, heat-insulating (phenolic) carb-to-intake spacer block in place, and install a heat shield plate that sandwiches between the carb and the spacer block. Make sure the carb float level is set to spec.
 
Yes, That Edelbrock is like an Aluminum tea kettle. You need a Phenolic (wood) or serious plastic spacer between the carb and the stovetop, ie intake. A air-gap intake is a little better but after the car shuts down, there is no moving air to cool the intake and it starts to heat up. MLS insulators are very good too, but a nice wood spacer will do wonders, and an electric fuel pump helps too. Mt Thermoquad even did this before a spacer was installed.
 
pishta said:
You need a Phenolic (wood) or serious plastic spacer
Click to expand...

Phenolic is not wood. Wood is not phenolic.

an electric fuel pump helps too
Click to expand...

An electric fuel pump is a band-aid on the problem of vapour lock, not a solution to the problem of percolation—the two are not the same—and electric fuel pumps are a hassle to do right (safely) on carbureted vehicles.

Percolation cannot be solved by installing an electric fuel pump, because the hard starting is caused by a flooded engine, which results from fuel boiling in the carburetor and collecting in the intake manifold. It does not matter what kind of fuel pump is on the engine; the fuel that causes the flooding is already in the carburetor.
 
Had the same issue with my 318 built dart performer intake. Found out if I just put the gas peddle about an 1/8" down it fired right up. I also raised the idle just a tad made a world of difference. I already have a 1/2 spacer witch didn't help. I posted the same issue and your not the only one seems to be a common problem.
IMG_1193.jpg
 
I have been fighting this problem for over a year now. It has got better but it still happens, especially during the warm southern summer when it gets in the upper 90s. I have a brand new Edelbrock 600, switched to a cast iron stock 4 barrel manifold, installed a 1/2" wood spacer (made the most improvement of anything so far), replaced the fuel pump, had a plate made to put behind the fuel pump & shield it from the exhaust manifold heat, rerouted my heater hoses over to the inner fender, wrapped the fuel line in heat wrap, took the carb apart & adjusted everything possible. My car no longer strands me but it starts hard every time after it has been sitting 20-45 minutes. It is very frustrating. I am also planning on replacing the starter & battery soon in hopes of maybe getting quicker starts from newer parts. Just chiming in & hopefully helping.
 
the problem is that the fuel is boiling on the metal lines... running a regulator with a return line will fix the problem... allows the fumes to head back the the tank and new fuel to be pumped in
 
how much black rubber hose do you have on your fuel line.?
 
I'm nearbout certain that vapor lock, fuel perk, boiling whatever the hell you wanna call it is your problem. But, I gave a diagnosis. I would try that first, because it's free if you have clothespins or real cheap if you don't. You never know....it could be something else. Better to be safe than sorry.
 
StrokerScamp said:
I'm nearbout certain that vapor lock, fuel perk, boiling whatever the hell you wanna call it is your problem. But, I gave a diagnosis. I would try that first, because it's free if you have clothespins or real cheap if you don't. You never know....it could be something else. Better to be safe than sorry.
Click to expand...

lol I had to put wood clothes pins on my 66 and it cured that car. I may have too many as they are spaced about every 3 inches.
 
slantsixdan said:
Phenolic is not wood. Wood is not phenolic.



An electric fuel pump is a band-aid on the problem of vapour lock, not a solution to the problem of percolation—the two are not the same—and electric fuel pumps are a hassle to do right (safely) on carbureted vehicles.

Percolation cannot be solved by installing an electric fuel pump, because the hard starting is caused by a flooded engine, which results from fuel boiling in the carburetor and collecting in the intake manifold. It does not matter what kind of fuel pump is on the engine; the fuel that causes the flooding is already in the carburetor.
Click to expand...
X2! The only thing I can add is sometimes a lower temp thermostat helps both problems.
 
Crappy gas doesn't help our problems either.....1/2" phenolic plate on my bee did wonders.


Mop
 
I went down this road and did all the above.

I have a 30 over 360, .474 Mopar cam, Performer intake, tti headers, 750 HP carb, stock fuel pump, electric fan on front of rad thermo controlled , manual fan.

The one inch phenolic spacer did wonders but every so often I had the heat soak problem.


The overall best answer to my problem was a Griffin aluminum radiator!!!

The more efficient radiator dropped the temperature of the motor therefore dropped the temperature of the engine bay as a whole. I could even feel the difference while driving down the road. The whole car runs cooler now. I was amazed at the difference it made to the entire car in the hot summer heat.
 
I would add a pusher cooling fan in front of the radiator,
that is thermostatically controlled. This way the fan can continue
to cool down the underhood after the car is turned off.

The electric fan is wired up via a relay, with the thermocouple on the back of the radiator controlling when the fan goes on/off.
It comes on when the temp is warmer than normal, like on a Hot day,
or if the traffic is moving slow.It makes a difference, and was worth the aprox $100, for the fan and control/relay kit.

http://www.forabodiesonly.com/mopar/showthread.php?t=111326
 
According to this thread I have everything wrong (even A/C, and headers) but I don't have the problem. I think mullinax95 is right about the big aluminum radiator. I do have a BeCool aluminum radiator and electric fan. She will start in 100 degree weather after running with the A/C.

This might help also: I do have a hole in the hood for the scoop, for street use it lets the heat out while stopped. You can actually see the heat waves getting pushed out by the radiator fan. I pull the air cleaner cover off and replace it with a rubber duct for drag racing, but for the street I guess that big hole must really help. So with modern low boiling point gas you have to cool the carb and gas lines somehow.
 
Thanks for the inputs, I will try some of these and get back to you on which one fix the problem.
 
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