Carburator question

[Mach1JB]

Guys,

I have the following problem and realy don't know jow to solve it.

My 351CJ has an Edelbrock manifold and carb.

When i park the car for a couple of days an try to start in again it won't start.

When i pour gasoline directly in the carb it starts right up and keeps running fine.

Short stops are never a problem , car will always start right away.

I think when i park the car for a few days , somehow the carb looses it's gasoline and the gasoline ends up in the fueltank.

Is there something wrong with my Edelbrock carb ??

Or how can i solve this problem ??

JB

 

[Don C]

There's really no way that the fuel could siphon back to the fuel tank.

Because of the way that Edelbrocks are designed they won't leak into or onto the engine like Holleys do with a blown power valve or leaking accelerator pump.

How long have you had the carb? Did this just start, if you've had it for some time? A possibility is a porosity that is allowing fuel to leak into the intake manifold.

 

[hyena429]

sounds like too me you got a weak fuel pump that mite be getting ready to go.....and it does well once its primed...But need a kick too get it going once it sets for a few days....I had a old blue ford truck do that to me...And one day it lost prime totaly and wouldnt pump back up...I pulled the fuel pump out and i could wiggin the piston up and down..lol..It had no pressure or seals left in it pretty much.

 

[VegasFastback]

My carter does the same thing, espically in summer. What I think happens is the vents in the top of the carb allow the gas to evaporate out of the bowls after a few days so when you goto start it again they have to refill before fuel can go through the carbs idle circuit. I usually only have to crank it a couple times before it'll startup if it has sat more the 3 or 4 days.

 

[Jeff73Mach1]

plus one on the fuel pump being close to failure.

An engine will run with a almost completely shot fuel pump by siphoning fuel- It will not however start pumping once the siphon is broken.

Check the fuel filter and pull and check the fuel line and you can put a pressure gauge on it and see what it does while cranking.

 

[73 MACH 1 MAN]

I would also check the accelerator pump. If its not working correctly it would cause this problem. Simply remove the air filter and kick the throttle a couple of times. You should see gas squirting into the venturi's if you dont see it squirting it could be the diaphram in the accelerator pump is bad! Easy to replace!

Edit: I see you said its an edelbrock carb, I think thier based off the old Caters so unlike the motorcrafts and holley which the acc punps are external the edelbrock acc. pump is internal still works the same way but a little harder to replacw

 

[Wolverine]

1. Just a caution...You shouldn't need more than a teaspoon of gas to get the car started. Raw gas into your cylinders is a good way to do some scoring.

COLD CAR, NOT RUN FOR A COUPLE OF DAYS...

2. Look into the carb and see if you gently pump the throttle do you get fuel. If so, then you have operator error in regards to starting.

3. If you do not see fuel, you can remove the fuel line at the fuel pump. It should be FULL of fuel. If not, and fuel is not leaking, perhaps....

WARM CAR, not hot...

4. Once you get the car running, warm but not HOT, shut off the car, and look into the carb. When GENTLY pumping the throttle you should see fuel. If not, I would suspect the accelerator pump.

5. (Long shot...) Do you have a vented gas cap? This could create a vacuum in the tank and suck the gas back into the tank when the car is sitting. Next time after a nice long drive and you have shut your pony down, remove the gas cap and then replace it. See if you can start it in a couple of days.

6. Do you have a choke?

I hate to tell someone how to start their pony(really...well except for Q), but if you DO see fuel in the carb after the car has been sitting for a couple of days, what is your start up procedure? Typically one pump to squirt fuel and set the choke should do it.

 

[pegasus]

an electric fuel pump will solve the priming issue, instant fuel, fully primed every time, just flick the on switch and your away....

Carter make a good pump for street use, which does not need a regulator..

 

[guys72Mach1]

Sounds like a choke issue. I would check your choke position when you first crank it over. Maybe adjust it back to open a little more. Also, lube up all your linkage on around the choke and throttle body base. A little bit of white lithium works will keep it lubed for ever.

Before you crank it are you giving it any gas? If not, may want to try putting your foot all the way to the floor one time then letting off. Give it a crank and see if it liked it. May just need to get a little pump shot before you crank it.

 

[Mister 4x4]

Wow - it looks like you have a couple of different things to try. I would be suspect of the fuel pump losing syphon. My Jeep had the same exact issues with starting as you describe - the fuel pump solved that part of it.

But then I was having problems with the carb itself - if I even breathed on the gas pedal while cranking, it would flood and I'd never get it started. After a rebuild and adjustments, it ran like a champ. The choke was way out of where it needed to be, and the float was off as well (it was a stock Jeep Carter AFB 1bbl - easy enough to rebuild... but it never lasted more than 6 months).

So I would change the fuel pump, then check the settings on your carb (starting with the choke). If the choke is engaging while the 'cold' temp is over 70 degrees, I'd adjust that out of there. I'm not sure what the breakover point is to 'need' choking during a cold start, but in my experience with a 'cold-natured' 32-yr-old Jeep, choking anything over 70 just means a dead battery from all the cranking and not starting.

 

[JimNiki]

an electric fuel pump will solve the priming issue, instant fuel, fully primed every time, just flick the on switch and your away....

Carter make a good pump for street use, which does not need a regulator..

That's the one I've got... works perfect. (Carter gold)

Even installed a holley electronic fuel pressure gauge to keep an eye on it. Stays on about 5 psi even at 5000 rpm... very stable.

 

[Mach1JB]

Wow guys , thought i asked you all a simple question LOL.

When i start my 64 Stingray ( i know , and i'm realy sorry ) with the Carter AFB,i put my foot all the way to the floor one time then letting it off.

It always starts the first time ,even when i park it for a couple of months.

The Edelbrock ( with automatic choke ) came with the Mach1 and was overhauled by Edelbrock in 2011.

Got some good advice from you guys, i'm gona work on the car next wednesday and keep you informed.

Thanks folks,

JB

 

[c9zx]

My carter does the same thing, espically in summer. What I think happens is the vents in the top of the carb allow the gas to evaporate out of the bowls after a few days so when you goto start it again they have to refill before fuel can go through the carbs idle circuit. I usually only have to crank it a couple times before it'll startup if it has sat more the 3 or 4 days.

+1 Chuck

 

[Mach1JB]

My carter does the same thing, espically in summer. What I think happens is the vents in the top of the carb allow the gas to evaporate out of the bowls after a few days so when you goto start it again they have to refill before fuel can go through the carbs idle circuit. I usually only have to crank it a couple times before it'll startup if it has sat more the 3 or 4 days.

+1 Chuck

Should i get rid of the Edelbrock and put on the original carb ??

JB

 

[c9zx]

My carter does the same thing, espically in summer. What I think happens is the vents in the top of the carb allow the gas to evaporate out of the bowls after a few days so when you goto start it again they have to refill before fuel can go through the carbs idle circuit. I usually only have to crank it a couple times before it'll startup if it has sat more the 3 or 4 days.

+1 Chuck

Should i get rid of the Edelbrock and put on the original carb ??

JB

I don't believe it would solve the issue you describe. Gasoline evaporates relatively quickly when exposed to the atmosphere through the bowl vent tubes. This is especially true when the temperature is elevated. As was previously mentioned, some on the site have installed an electric pump to refill the fuel bowl before starting the car. Chuck

 

[hyena429]

I would check your fuel pump first...Before replacing a whole carb....Its waaaaay cheaper...I have had many elelbrock carbs and never had the issue your talking about....the old blue ford truck i drove...had a holley on it...and started to do what you said yours did....finaly it just stopped runing ...and wouldnt prime again...a mechanical fuel pump are cheap and proably needs replaced anyways..even if it isnt the issue hehehe

 

[Tnfastbk]

So if its evaporating from the vent tubes, the next time you park it put a couple of the vacuum port caps over the vent and that will tell that story, just dont forget to remove them before the next drive:s

 

[c9zx]

So if its evaporating from the vent tubes, the next time you park it put a couple of the vacuum port caps over the vent and that will tell that story, just dont forget to remove them before the next drive:s

+1 Chuck

 

[Carguy4sp]

Did you solve this issue? I am having the same problem, I thought it was the heat from S. Florida location.