*Fuel system

set fuel pressure with engine running

Timdatoolman said:

what do yawll think? I just rebuilt my fuel system.

• running a 4160 750 Holley
• new niccop hard line

-added a return line from a new added regulator ( was putting out about 9 or 10 lbs so I incorporated the regulator)
- using the mechanical pump
-ran my lines on the outside of the frame with 100 micron filter near the back & 30 micron right before carb.
- rebuilt carb

about to fire up, just got to get gas.
Is there anything I'm missing?

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Well, I got the car started after putting a few drops of gas in the carb & it dies after about 7 seconds. it burns the gas I put in & then runs a little longer & dies. I adjusted the regulator & float bowls but no luck. Anybody have any ideas? Thanks

Unhook fuel line and ignition. Run hose into container. Confirm fuel flows when cranking motor over. Then its just the regulator, filter and the carb. Make sure the regulator is facing correctly if directional.

Can also get small squirt bottle like a round ketchup one and fill bowls with fuel thru vent. Helps give the carb a little time to get air out of fuel system.

how big is the return line and did you put an orifice on the return line. you might be flowing all the fuel back to the tank.

68Dart said:

Can also get small squirt bottle like a round ketchup one and fill bowls with fuel thru vent. Helps give the carb a little time to get air out of fuel system.

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I bypassed the regulator & going through a 30 micron filter directly to carb & now will not fire up at all. Almost seems like to much gas, I've adjusted fuel bowls a few times & still nothing.Of course battery dies & have3 to charge & wait.

hotrodg726 said:

how big is the return line and did you put an orifice on the return line. you might be flowing all the fuel back to the tank.

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return was 3/8

return line has to have an orifice to restrict flow back to the tank or there will be no pressure at the carb. from post #3 it sounds like the pump is not pumping. or getting fuel. check for vacuum leaks in the new tank to pump line. if there is a small vacuum leak it will suck air and not fuel.

So back at it, I took off the regulator & return line , I have great flow to the carb at about 6 psi. The car starts right up & idles good but then dies when I hit the throttle. ???????????????????????????? On my way to the nut house.

exactly what carburetor, cam, ignition timing, comression, engine size etc.

If you look down the carb with motor off, when you crack the throttle, do you see the squirter’s shooting fuel into front two throttle bores. If it just sort of dies, usually fuel related. Accelerator pump and squirter provides the fuel to cover up for cracking the throttle blades open (very simplified explanation for the pros on here).

Timdatoolman said:

So back at it, I took off the regulator & return line , I have great flow to the carb at about 6 psi. The car starts right up & idles good but then dies when I hit the throttle. ???????????????????????????? On my way to the nut house.

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What's the inside diameter of your fuel supply line to the carb? Sort of sounds like it's just barely able to keep up with the carb. Regardless of the pressure, insufficient volume won't work well.

hotrodg726 said:

exactly what carburetor, cam, ignition timing, comression, engine size etc.

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Holley 4160 750, with a mild racing cam (all I was told) 350 SBC.

68Dart said:

If you look down the carb with motor off, when you crack the throttle, do you see the squirter’s shooting fuel into front two throttle bores. If it just sort of dies, usually fuel related. Accelerator pump and squirter provides the fuel to cover up for cracking the throttle blades open (very simplified explanation for the pros on here).

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Yes, squirts fuel

tekctrl said:

What's the inside diameter of your fuel supply line to the carb? Sort of sounds like it's just barely able to keep up with the carb. Regardless of the pressure, insufficient volume won't work well.

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3/8 line, I took of the line just before carb & turned over & it was pumping the full ID of the line.

Idle rpm?
Timing at idle?
Timing at 2,000rpms?

If the squirter is squirting, you could be correct about it getting too much fuel and it's flooding. Is it hard to start again after it dies? If so, does it start right up again when putting a little fuel in the carb? Check a few plugs to see if any are wet right after it stalls. Is the regulator specifically for use with a return line? And of course, triple check to be sure the regulator is plumbed correctly.

55 Tony said:

And of course, triple check to be sure the regulator is plumbed correctly.

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This^^^^^
What's the brand and pt number on that regulator?
Use of a 3/8" line is not part of the problem.

Timdatoolman said:

3/8 line, I took of the line just before carb & turned over & it was pumping the full ID of the line.

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I was using the same size NiCop fuel line before I changed to flexible armored lines and AN fittings. When I removed the NiCop lines I found that there was a hidden kink in one bend. That had cut way down on the amount of fuel that the line could flow. Did your NiCop line go in before or after you started seeing this issue? Has it always done this? Did you change anything just prior to the start of the problem?