Hot start issue
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Tuned
Joined: Oct 2016
Posts: 255
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From: South dakota
Hot start issue
I have a 73 F-250 with a 390 edelbrock 4 bbl. When its cold it starts great but when you get it all warmed up well and shut it off for say 20 min then restart it acts like its flooded. But if you were to restart immediately after shutdown it starts fine. Its a 600 CFM edelbrock Carb #1406. not sure what to try to eliminate this issue?
Lead Driver
Joined: Oct 2018
Posts: 7,894
Likes: 2,372
I'd start by getting a Holley.
But other than that check to see if you have a insulator gasket under the carb. heat is the problem.
to avoid this I always toss the EGR and block off the crossover. if you wanted to boil a carb these features are perfect.
But other than that check to see if you have a insulator gasket under the carb. heat is the problem.
to avoid this I always toss the EGR and block off the crossover. if you wanted to boil a carb these features are perfect.
Grumpy goat
Joined: May 2017
Posts: 3,059
Likes: 597
Definitely insulate the carburetor with phenolic spacer, and get rid of the EGR.
It could be nothing more than your idle setting. In general, with a mild street engine, if your carb is set to idle above 700'ish, the transfer slots in the primary bores are exposed too much. That allows fuel to drip out when the engine isn't running, and allows too much fuel out on start up. It can also cause "dieseling" when you shut the engine down. Do you ever experience dieseling?
Try this. With the engine totally cold, try to start it without giving it a pump shot first. If it fires up, then it's probably the idle circuit flowing too much fuel and causing your hot start problems. If that's the case, adjust your idle screw counterclockwise a bit. A tachometer would help here. If you don't have one, you can pick up a cheap timing gun that has a tach display.
It could be nothing more than your idle setting. In general, with a mild street engine, if your carb is set to idle above 700'ish, the transfer slots in the primary bores are exposed too much. That allows fuel to drip out when the engine isn't running, and allows too much fuel out on start up. It can also cause "dieseling" when you shut the engine down. Do you ever experience dieseling?
Try this. With the engine totally cold, try to start it without giving it a pump shot first. If it fires up, then it's probably the idle circuit flowing too much fuel and causing your hot start problems. If that's the case, adjust your idle screw counterclockwise a bit. A tachometer would help here. If you don't have one, you can pick up a cheap timing gun that has a tach display.
Thread Starter
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Tuned
Joined: Oct 2016
Posts: 255
Likes: 2
From: South dakota
Yeah I have a tach and I Idle around 650-700 RPM, If I turn the idle down it idles really slow and stumbles until it clears out completely. I did order a .75 spacer fiber, for the carb and I also Ordered a Pressure gauge to see where My Fuel Pressure is running I got it coming from Summit Racing. IN a week or so I'll try this and see what happens. I never had it Diesel when I shut it off But I notice a odor of gasoline. Could my Metal fuel filter that's on top of the Intake Manifold Be playing a Role in this Issue? do I need to move my Fuel filter to a colder location?? thank you for any Advise
Lead Driver
Joined: Oct 2018
Posts: 7,894
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If you're baking your intake and carb with the crossover what little heat you're going to get in your line is minimal. vapor lock maybe but that's not your issue.
At the very least you might plug the EGR in the intake if it's not already. the smell of fuel you're noticing is the gas boiling out of your carb.
At the very least you might plug the EGR in the intake if it's not already. the smell of fuel you're noticing is the gas boiling out of your carb.
Thread Starter
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Tuned
Joined: Oct 2016
Posts: 255
Likes: 2
From: South dakota
Well I am gonna try the .75 fiber spacer between the carb and intake when I get it will see then
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Fleet Mechanic
Joined: Feb 2004
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From: Arlington,Wa
I used a 1 inch phenolic carb spacer between my Edelbrock 750 and Performer intake on a 460...no problems.( I'm aware your running a 390...but I think the same logic applies to the carb boiling issue)
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Lead Driver
Joined: Nov 2006
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From: Pa.
If the carb boils frequently, keeping in mind you may be missing it boiling part of the time because it boils mostly after you walk away because that's when it will boil after you park and the motor is unable to cool itself unless you have an electric fan wired to stay on whenever the motor temp is higher than XXX. The boiling causes the float to flutter driven by the boiling gas. This can wear undermine the needle and seat to the point where it weeps into the intake creating a flooded condition when you try to start it next.
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