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Discussion Starter · #1 · (Edited)
I have a Holley 750 carb, eddlebrock airgap manifold on my 383, I have a summit brand fuel pump.

It seems as though my carb is flooding easily, it was difficult to start at times.

The passanger side of the carb looks as though it has chokes attachement but is not hooked up to anything.

I will post pictures either tonight or tomorrow, I just want to get the thing running.

Also a huge mist of fuel fumes shot up out of the front of the car and at one point caught fire and stayed burning until i was able to smother it.
 

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Home School Valedictorian
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It is a manual choke carb, everything that is needed on the carb is there, you need a choke cable attached to the choke linkage and ran to the interior.
You also need to cap the exposed vacuum port on the front metering block if it isn't being used.
On second look there is a open port on the throttle plate also under the front float bowl.
 

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The Smell of Nitro in the morn
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What is the pressure the fuel pump putting out ?
In the Knowledge Base on this site has numerous info on tuning Holley carbs.

Explain what happens when you give it gas ?
What color are the plugs ?
If you get stuck send me a PM.
 

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Discussion Starter · #9 ·
1BAD80 said:
What is the pressure the fuel pump putting out ?
In the Knowledge Base on this site has numerous info on tuning Holley carbs.

Explain what happens when you give it gas ?
What color are the plugs ?
If you get stuck send me a PM.
have not looked at the plugs, I was able to mess with the timing and plug the vacums and it isn't backfiring, right now, but I am unsure as how to and what to hook the choke up to.

I have not looked at the plugs yet, but I think it is running rich, flames were shooting out of the headers, when i had it running wirh open headers


the fuel gauge is reading about 6
 

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sounds like you have a timing light problem, not a carb problem. :D

low timing makes the engine backfire and the headers to glow red. It also makes the engine require more throttle opening to idle. This puts the carb throttle blades past the idle circuit (past the transfer slots) and makes the engine run rich.

If the idle mixture screws don't do anything or there is vacuum on the ported vacuum source, then the throttle blades are open too far at idle.
 

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Discussion Starter · #13 ·
454C10 said:
sounds like you have a timing light problem, not a carb problem. :D

low timing makes the engine backfire and the headers to glow red. It also makes the engine require more throttle opening to idle. This puts the carb throttle blades past the idle circuit (past the transfer slots) and makes the engine run rich.

If the idle mixture screws don't do anything or there is vacuum on the ported vacuum source, then the throttle blades are open too far at idle.

In the 3rd pic i posted you see the 2 front vacume lines open, can you tell me what to do with them? plug them or run them somewhere.

my accell super coil set up does have a vacume canister on it, i dont know which one to hook it up to. I also would not know what to do with the other one.
 

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one should be a ported vacuum source and the other a manifold vacuum source.

The manifold vacuum should be sucking all the time. The ported source should not be sucking at idle. The ported source only has vacuum past idle.

plug the ported source as it is an emission device.

use the manifold vacuum source for the vacuum advance. unplug it, set the initial timing to 15, then plug the vacuum canister back in. Timing should go up to 30 degrees at idle. This will make the idle increase, so turn down the throttle blades (idle screw) and adjust the idle mixture screws for best idle.
 

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Discussion Starter · #15 ·
454C10 said:
one should be a ported vacuum source and the other a manifold vacuum source.

The manifold vacuum should be sucking all the time. The ported source should not be sucking at idle. The ported source only has vacuum past idle.

plug the ported source as it is an emission device.

use the manifold vacuum source for the vacuum advance. unplug it, set the initial timing to 15, then plug the vacuum canister back in. Timing should go up to 30 degrees at idle. This will make the idle increase, so turn down the throttle blades (idle screw) and adjust the idle mixture screws for best idle.
this would give me an overall timing of 35/36 degrees.

Ericnova suggested 36 degrees advanced for my motor.
 

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Discussion Starter · #17 ·
454C10 said:
36 to 38 is a good number. try different total timing to see what works best for your engine.
will do thank you !!!!!!!!!!

also i didnt post this earlier, but it is in a 68 el camino, and I have a 700r4 behind it.

dont know if these things matter, but someone posted that i should run a manual choke to the dash, and i dont think i want to do that.
 
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