5 psi should be plenty. If it should starve for fuel I would check the size of the line from the pump to the regulator. Is it 3/8" or better?
Fuel delivery woes
Thread Starter
Racer
Joined: Sep 2015
Posts: 250
Likes: 29
Fuel delivery woes
Hi all, question on an issue i'm pursuing right now with my fuel delivery.
1980 with new 383. I've been trying to get my fuel pressure up to 6psi which is what the carb builder recommended.
I'm using a mechanical fuel pump and a holley regulator with bypass. I'm using the factory hard fuel lines for the inlet to the regulator and the return line for the bypass on the regulator. From the regulator, i'm using all -6 AN fuel lines and fittings which next go to an inline fuel filter, then to the fuel log and to the dual fuel inlets on the carb.
I've replaced the fuel pump which is rated for 6.5 to 8 PSI. I've put in place a new regulator and with the engine running the max fuel pressure i can get is 5psi.
First, i'm starting to suspect my fuel tank may be dirty since across 2 carbs i've had my float stick due to trash in the bowl. Each time, i've pulled the fuel filter and didnt find anything so that parts still a mystery.
Second, could it be the diameter of my fuel lines ? Could it be the hard line and -6 AN lines are not able to deliver enough fuel to get 6psi of pressure ?
If i end up pulling the tank and replacing it, i may just switch to an electric pump and run new fuel lines.
Any ideas where to look next ?
1980 with new 383. I've been trying to get my fuel pressure up to 6psi which is what the carb builder recommended.
I'm using a mechanical fuel pump and a holley regulator with bypass. I'm using the factory hard fuel lines for the inlet to the regulator and the return line for the bypass on the regulator. From the regulator, i'm using all -6 AN fuel lines and fittings which next go to an inline fuel filter, then to the fuel log and to the dual fuel inlets on the carb.
I've replaced the fuel pump which is rated for 6.5 to 8 PSI. I've put in place a new regulator and with the engine running the max fuel pressure i can get is 5psi.
First, i'm starting to suspect my fuel tank may be dirty since across 2 carbs i've had my float stick due to trash in the bowl. Each time, i've pulled the fuel filter and didnt find anything so that parts still a mystery.
Second, could it be the diameter of my fuel lines ? Could it be the hard line and -6 AN lines are not able to deliver enough fuel to get 6psi of pressure ?
If i end up pulling the tank and replacing it, i may just switch to an electric pump and run new fuel lines.
Any ideas where to look next ?
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Thread Starter
Racer
Joined: Sep 2015
Posts: 250
Likes: 29
Thread Starter
Racer
Joined: Sep 2015
Posts: 250
Likes: 29
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
I actually changed the sender and sock via the fuel door. Rubber lines too. Just have to be patient.
The sock was collapsed.
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Drifting
Joined: Sep 2006
Posts: 1,986
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From: Columbus MN
I had my tank out of the car because I modified the lines in and out, but I am pretty sure you can replace the sock filter from the top without removing the tank from the car.
Thread Starter
Racer
Joined: Sep 2015
Posts: 250
Likes: 29
I have an '80 also and worked inside the tank when I switched to EFI. Your tank is lined, no bladder.
I had my tank out of the car because I modified the lines in and out, but I am pretty sure you can replace the sock filter from the top without removing the tank from the car.
I had my tank out of the car because I modified the lines in and out, but I am pretty sure you can replace the sock filter from the top without removing the tank from the car.
