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-   -   hard starting with new Edelbrock when warm (https://67-72chevytrucks.com/vboard/showthread.php?t=398626)

D-Rat 04-21-2010 12:36 PM

hard starting with new Edelbrock when warm
 
The 1406 on my 400 makes cold starts a breeze...fires up on the first crank every time. The problem is when the truck is warm, it doesn't like to start and usually requires me to pump the gas pretty good while turning the starter. Eventually it catches.

What do I need to adjust? The carb is brand new and unaltered. Let's assume timing is fine becuase this was not an issue with the previous carb, though it did have other issues.

I'm also down on "stab it" power compared to the 730CFM Holley I took off. Ideas?

I'm not crazy about rejetting, etc., as I've never torn one of these down, but if that's the only option, well...

Tkmadone 04-21-2010 01:09 PM

Re: hard starting with new Edelbrock when warm
 
Sounds too rich. Next hot start don't pump it, just hold the throttle half open and crank. If it starts right up then you are definitely too rich.

71tahoe 04-21-2010 01:12 PM

Re: hard starting with new Edelbrock when warm
 
Your "stab it" power is down because it's only 600cfm.

cdowns 04-21-2010 01:19 PM

Re: hard starting with new Edelbrock when warm
 
do you have a carb spacer like edelbrock recomends in the instruction booklet so that the fuel doesnt boil

mclairmo 04-21-2010 01:29 PM

Re: hard starting with new Edelbrock when warm
 
Is the choke plate open when it is warm? If not, then the choke is not working and it needs to be fixed/replaced. When you pump the gas, you are actually opening the butteflies and allowing more air to enter, which is what the engine needs when warm. A warm engine should not need to be pumped to start up. However, when the engine is cold the choke plate needs to be closed, which explains why your cold starting is great. A closed choke plate will also kill your power. The cfm is fine for your engine and should not be a source of your "stab it" power issues.

Leviticus 04-21-2010 02:20 PM

Re: hard starting with new Edelbrock when warm
 
Are you getting any hesitation on take off? And re-jetting an Edelbrock is quite simple, and can be done while it is on the engine although I doubt this is your starting problem. Edelbrock makes a nice jet kit for this. Also, like Cdowns said, a spacer is recommended.

What type of choke did you get, electric or manual?

even though your last carb worked well, its a good time to check you timing anyways. The PO of my truck had the timing way to advanced and it would be a bear to start in certain conditions.

CharlieBrown 04-21-2010 02:24 PM

Re: hard starting with new Edelbrock when warm
 
Quote:

Originally Posted by cdowns (Post 3932909)
do you have a carb spacer like edelbrock recomends in the instruction booklet so that the fuel doesnt boil


Thats what I would guess

D-Rat 04-21-2010 02:33 PM

Re: hard starting with new Edelbrock when warm
 
Choke is working fine.

There is no carb spacer. It's bolted directly to the manifold with just the gasket in between. That explanation makes sense.

What part are others running here? How thick? Anyone have one laying around they're not using?

Leviticus 04-21-2010 02:41 PM

Re: hard starting with new Edelbrock when warm
 
Quote:

Originally Posted by D-Rat (Post 3933038)
Choke is working fine.

There is no carb spacer. It's bolted directly to the manifold with just the gasket in between. That explanation makes sense.

What part are others running here? How thick? Anyone have one laying around they're not using?

Do you have a spread bore or square bore intake?

CharlieBrown 04-21-2010 02:52 PM

Re: hard starting with new Edelbrock when warm
 
my truck has a dual plane intake..never boiled

my surburban has a open intake..it boiled until I installed the spacer

D-Rat 04-21-2010 03:05 PM

Re: hard starting with new Edelbrock when warm
 
Quote:

Originally Posted by Leviticus (Post 3933049)
Do you have a spread bore or square bore intake?

Not sure I know the difference, but it's one big hole. It's an Edelbrock RPM intake if that helps.


I'm looking at spacers...which is better - open design or 4 hole?

CharlieBrown 04-21-2010 03:07 PM

Re: hard starting with new Edelbrock when warm
 
use the 4 hole

that should stop your problems..and it will also help you idle circuit

Leviticus 04-21-2010 03:26 PM

Re: hard starting with new Edelbrock when warm
 
Quote:

Originally Posted by D-Rat (Post 3933092)
Not sure I know the difference, but it's one big hole. It's an Edelbrock RPM intake if that helps.


I'm looking at spacers...which is better - open design or 4 hole?

If it is one open passage (not divided) than you most likely have a single plane square bore. You should be able to pick up a carb spacer at your local auto parts store/speed shop.

Just make sure it will match your carb and intake. The 4 hole designs should help as well, as Charlie said.

Here is a pic of a spread bore dual plane intake for reference.

http://i38.photobucket.com/albums/e1...delbrock20.jpg

Eddie H. 04-21-2010 03:46 PM

Re: hard starting with new Edelbrock when warm
 
I had the same problem until I installed a 4 hole plastic spacer to insulate the carb from the manifold heat.

piecesparts 04-21-2010 03:50 PM

Re: hard starting with new Edelbrock when warm
 
Definitely sounds like a "Heat Soak" issue. I would try the phenolic spacer to remove the heat from the bowls of the carb. I am running one on my stroker engine with the Edelbrock carb and intake.

D-Rat 04-21-2010 04:28 PM

Re: hard starting with new Edelbrock when warm
 
Nabbed a 1/2" one off ebay new with gaskets and studs for $22.99 shipped. Will see how that works. Thanks guys.

AH619 04-22-2010 05:31 PM

Re: hard starting with new Edelbrock when warm
 
Most of the edelbrocks i have require about 1/4 throttle push with no pumping when warm. I have been told that all these drip a little fuel out the bottom? Sometimes i give mine 1 pump before i start it?

JCA1972 04-22-2010 10:38 PM

Re: hard starting with new Edelbrock when warm
 
Hey D-RAT I'm having the same problem with my 1406, I had a 1405 and it would start fine every time, the 1406 takes a while to start when hot, I have an edelbrock performer intake so it has the 4 holes. let me know if that spacer fixes the problem.

D-Rat 04-23-2010 01:46 PM

Re: hard starting with new Edelbrock when warm
 
will do.

Shyguy 04-23-2010 01:54 PM

Re: hard starting with new Edelbrock when warm
 
Don't me to hijack, but since you all are talking about Edelbrock carbs.

What would be the best one for my stock '73 454 with an manual transmission.

Thank you.

Danny

D-Rat 04-23-2010 04:06 PM

Re: hard starting with new Edelbrock when warm
 
The 600CFM is marginal for my small block 400 but might work ok on a bigger motor with larger jets. A stock '73 454 is pretty low compression and probably doesn't have much in the way of high flow heads, so you might not get much benefit out of anything larger.

D-Rat 04-25-2010 11:30 AM

Re: hard starting with new Edelbrock when warm
 
Spacer seems to have done the trick!

Crazy 10-28-2014 05:14 PM

Re: hard starting with new Edelbrock when warm
 
Iv got the same problem, and my motor also diesels when ever i get to my destination and shut it down will the spacer fix this as well.


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