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Old 08-16-2019, 10:06 AM   #1
elorenzof
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New Edelbrock Carb - hard start when warm

Good Morning,

On my small block i have installed a new Edelbrock Carburetor and Performer Intake Manifold. The truck starts and runs great. When Cold. Except she is hard to start when warmed up after driving for a bit. Like going to the Grocery Store where you have to shut her off for a few minutes and then you come back out and it's crank crank crank pedal down to the floor and maybe she will start but struggle to start.. any ideas?
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Old 08-16-2019, 10:27 AM   #2
68 P.O.S.
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Re: New Edelbrock Carb - hard start when warm

That is one of the design flaws of Edelbrock carbs, fuel percolation. They're known for flooding too. Once corrected and calibrated, they're great, low maintenance carbs. You have to buy a heat insulating gasket for it to cure the percolation/hard starting. Which Performer intake do you have, a square bore or spreadbore? If it's a square bore, you need Edelbrock's 9266 (it's cheap too). To stop flooding issues, the float levels must be set to specs (they're always off right out of the box due to shipping & handling) and the fuel pressure must be limited to no more than 5.5 psi with a pressure regulator or the Edelbrock fuel pump.
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Old 08-16-2019, 11:18 AM   #3
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Re: New Edelbrock Carb - hard start when warm

I’d suggest a thicker spacer like this.
https://www.summitracing.com/int/par...iew/?rrec=true

And when you check your float levels set them 1/8 inch lower. You need them lower due to your elevation.
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Old 08-16-2019, 12:47 PM   #4
elorenzof
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Re: New Edelbrock Carb - hard start when warm

Gentlemen thank you for the replies. i am going to do both suggestions. fuel pressure regulator and spacer. Thank you! Do you think other than adjusting the float i need to do anything else ie: re-jet the carb?
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Old 08-16-2019, 02:43 PM   #5
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Re: New Edelbrock Carb - hard start when warm

Likely no need to re-jet.
Maximize your timing though.
Bump your initial up to 14 degrees.
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Old 08-16-2019, 03:01 PM   #6
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Re: New Edelbrock Carb - hard start when warm

Both of my old trucks have Holley carbs.... different, but when they're warm they start great if I don't touch the accelerator pedal. If I forget and step on the pedal they have to turn awhile to start.
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Old 08-16-2019, 04:38 PM   #7
akart
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Re: New Edelbrock Carb - hard start when warm

I have the same carb and manifold,I like them. Yes,adjust the floats to 7/16", IMO that suggestion to set them 1/8" lower is bogus. Lean and rich is done w/rods and jets. I put in the 1" spacer also the Edelbrock fuel pump (not cheap) but they match up to that carb,no starting problems,pops right off any time. W/ a regulator you would also need a gauge which is too fiddlie for me.Just put in the ED fuel pump and forget it. As to rejetting I would suggest you do it. These carbs come set rich. Get the kit w/rods,jets and springs, there are a lot of tuning options there power/economy. Just switched rods to the 75/47 as per recommendation on this forum,mileage went up. You can switch the rods w/the carb on the truck but jets take the carb off. I just put on Summit 72cc iron heads,Hedman headers,dual 2 1/2" exhaust and my mileage went up from 11/12 to 14/15 if I keep my foot off it. These carbs are easy to work on, good luck. By the by my timing is set @12, truck didn't like 14,was hard to start and back fired.

Last edited by akart; 08-16-2019 at 04:54 PM. Reason: addition
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Old 08-16-2019, 08:43 PM   #8
elorenzof
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Re: New Edelbrock Carb - hard start when warm

I wonder why there are so many options that work for different owners and trucks? One option may work for one but not the other it does get confusing as to which one would be correct
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Old 08-17-2019, 09:54 PM   #9
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Re: New Edelbrock Carb - hard start when warm

Check out the Edelbrock site for making changes to your carburetor. When I bought my Edelbrock 600 CFM carb new it came with a DVD detailing how to set it up. In my case I had to richen the mixture a bit by going to smaller metering rods to get rid of an off idle stumble at low throttle volume. Consider that the trucks' setup may have variations in back pressure and cubic inches. Quadrajets are used over a wide range of engine sizes; there are many differences in their calibration as a result.
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Old 08-18-2019, 02:50 PM   #10
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Re: New Edelbrock Carb - hard start when warm

Verify that the choke is not closed when you doing the hot restart before doing anything.
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Old 08-20-2019, 08:44 AM   #11
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Re: New Edelbrock Carb - hard start when warm

I fix all my Edelburp issues by throwing them away and installing Holleys.
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