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Loss of fuel pressure #3279532
01/01/25 09:14 AM
01/01/25 09:14 AM
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Madison Wi
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Looking for some suggestions here
My gauge isnt great but it's new and currently accurate. I'll upgrade to a better gauge soon

Fuel system
Barry Grant 280 pump with -10 ports
Stock 65 gas tank with welded in sump
Moroso -8 inline fuel filter
Maga fuel four port regulator with return
Lines from tank to regulator are -8
Lines from regulator to carbs are -6
Two Holley 450's on a 383 tunnel ram.
Tank recently dropped and cleaned out.
I don't see anything in the fuel filter
Cap is vented

Once the fuel pressure drops to zero in the vid, I shut the pump off then back on and the fuel pressure comes back.

I'm thinking there is something in the tank blocking the sump port, but before I dig back into that does anyone see anything wrong with the fuel system hard part selection? ( Aside from the gauge 😏)

Appreciate any thoughts. This vid is about 1/2 throttle...... It's a bit cold and damp out

https://youtu.be/CR9SMVem7T4?si=5GneXC8UN8ZKau8K

Last edited by NTOLERANCE; 01/01/25 09:19 AM.

I used to care but....... things have changed
Re: Loss of fuel pressure [Re: NTOLERANCE] #3279535
01/01/25 09:23 AM
01/01/25 09:23 AM
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ruderunner Offline
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I'd like to know about the electrical side of the pump. Is it losing power? Just not enough power?


Angry white pureblood male
Re: Loss of fuel pressure [Re: ruderunner] #3279551
01/01/25 09:56 AM
01/01/25 09:56 AM
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Madison Wi
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Originally Posted by ruderunner
I'd like to know about the electrical side of the pump. Is it losing power? Just not enough power?


Battery is in the trunk. There's a 30 amp relay sending power to the pump. Wires are 12ga?? I can't recall exactly. Pump is under the car right under the battery. The pump is loud and there is a never a change in the pitch of the pump

I might have to physically lower the pump some. It's about an inch above the sump port.

Last edited by NTOLERANCE; 01/01/25 10:02 AM.

I used to care but....... things have changed
Re: Loss of fuel pressure [Re: NTOLERANCE] #3279595
01/01/25 11:32 AM
01/01/25 11:32 AM
Joined: Jan 2003
Posts: 22,188
A collage of whims
topside Offline
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I'll share an experience I had many years ago, with my Hemi car.
1/2" fuel line starting at the tank pickup, had the tank out for some reason at a buddy's shop.
Car would run great for awhile, and then starve for fuel & quit.
After sitting for a minute or two, would start right up & run great again for a while, then repeat.
I went through everything, no change, and eventually pulled the sending unit and peered into the tank with a flashlight.
I saw a shop towel in there. I figured it was getting sucked to the pickup hose and blocking supply.
I'd been pranked.
Removed the rag and all was well.

I still owe that guy a payback, but I live in fear of a Karma strike...

Re: Loss of fuel pressure [Re: NTOLERANCE] #3279632
01/01/25 12:16 PM
01/01/25 12:16 PM
Joined: Jan 2003
Posts: 4,395
Morrow, OH
markz528 Offline
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Originally Posted by NTOLERANCE
Looking for some suggestions here
My gauge isnt great but it's new and currently accurate. I'll upgrade to a better gauge soon

Fuel system
Barry Grant 280 pump with -10 ports
Stock 65 gas tank with welded in sump
Moroso -8 inline fuel filter
Maga fuel four port regulator with return
Lines from tank to regulator are -8
Lines from regulator to carbs are -6
Two Holley 450's on a 383 tunnel ram.
Tank recently dropped and cleaned out.
I don't see anything in the fuel filter
Cap is vented

Once the fuel pressure drops to zero in the vid, I shut the pump off then back on and the fuel pressure comes back.

I'm thinking there is something in the tank blocking the sump port, but before I dig back into that does anyone see anything wrong with the fuel system hard part selection? ( Aside from the gauge 😏)

Appreciate any thoughts. This vid is about 1/2 throttle...... It's a bit cold and damp out

https://youtu.be/CR9SMVem7T4?si=5GneXC8UN8ZKau8K


Good ole BG280 pump! Such memories of mine doing the same thing as yours!

Has it ever worked in your application?

Will try to keep my story short. Back when you were able to buy these new, I put one on my race car. Ran high 10's. Worked great. Sprung a leak under warranty. Get it back and it acted just like yours. Basically lost all pressure going down the track. I did fuel flow testing by metering into a gas can with a ball valve. Turn it on and its good then all of a sudden it goes into resonance and starts sputtering instead of flowing. Increase it more and it was fine. The gauge feeding the regulator went crazy. BG had no clue. Sent me a new pump. Same problem. They ended up replacing the BG280 with a BG400. Still running it today.

I'm afraid if you have the same problem as mine, you have a fundamental pump design issue that you will only solve with a different pump. At last I never figured it out. It is a Chinese copy so they never really understood the design detail of the pump and probably got something wrong in the copy. Only difference with yours is you have a return line so it could be a different situation. I would recommend a ball valve test.

Last edited by markz528; 01/01/25 12:16 PM.

67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......
Re: Loss of fuel pressure [Re: topside] #3279645
01/01/25 12:31 PM
01/01/25 12:31 PM
Joined: Aug 2003
Posts: 4,408
Madison Wi
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Originally Posted by topside
I'll share an experience I had many years ago, with my Hemi car.
1/2" fuel line starting at the tank pickup, had the tank out for some reason at a buddy's shop.
Car would run great for awhile, and then starve for fuel & quit.
After sitting for a minute or two, would start right up & run great again for a while, then repeat.
I went through everything, no change, and eventually pulled the sending unit and peered into the tank with a flashlight.
I saw a shop towel in there. I figured it was getting sucked to the pickup hose and blocking supply.
I'd been pranked.
Removed the rag and all was well.

I still owe that guy a payback, but I live in fear of a Karma strike...



This is what I'm thinking is happening. Something is stopping up the port. I have a second port. Thinking I try to run both -8 ports into the pump and see what happens.


I used to care but....... things have changed
Re: Loss of fuel pressure [Re: markz528] #3279648
01/01/25 12:35 PM
01/01/25 12:35 PM
Joined: Aug 2003
Posts: 4,408
Madison Wi
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Originally Posted by markz528
Originally Posted by NTOLERANCE
Looking for some suggestions here
My gauge isnt great but it's new and currently accurate. I'll upgrade to a better gauge soon

Fuel system
Barry Grant 280 pump with -10 ports
Stock 65 gas tank with welded in sump
Moroso -8 inline fuel filter
Maga fuel four port regulator with return
Lines from tank to regulator are -8
Lines from regulator to carbs are -6
Two Holley 450's on a 383 tunnel ram.
Tank recently dropped and cleaned out.
I don't see anything in the fuel filter
Cap is vented

Once the fuel pressure drops to zero in the vid, I shut the pump off then back on and the fuel pressure comes back.

I'm thinking there is something in the tank blocking the sump port, but before I dig back into that does anyone see anything wrong with the fuel system hard part selection? ( Aside from the gauge 😏)

Appreciate any thoughts. This vid is about 1/2 throttle...... It's a bit cold and damp out

https://youtu.be/CR9SMVem7T4?si=5GneXC8UN8ZKau8K


Good ole BG280 pump! Such memories of mine doing the same thing as yours!

Has it ever worked in your application?

Will try to keep my story short. Back when you were able to buy these new, I put one on my race car. Ran high 10's. Worked great. Sprung a leak under warranty. Get it back and it acted just like yours. Basically lost all pressure going down the track. I did fuel flow testing by metering into a gas can with a ball valve. Turn it on and its good then all of a sudden it goes into resonance and starts sputtering instead of flowing. Increase it more and it was fine. The gauge feeding the regulator went crazy. BG had no clue. Sent me a new pump. Same problem. They ended up replacing the BG280 with a BG400. Still running it today.

I'm afraid if you have the same problem as mine, you have a fundamental pump design issue that you will only solve with a different pump. At last I never figured it out. It is a Chinese copy so they never really understood the design detail of the pump and probably got something wrong in the copy. Only difference with yours is you have a return line so it could be a different situation. I would recommend a ball valve test.


Thanks for the input. This pump came off another car that was running well before we installed it here as my previous bg280 oddly enough leaked and even after a rebuild wouldnt work right. 🤷

I'll check into a ball valve test. Thanks


I used to care but....... things have changed
Re: Loss of fuel pressure [Re: NTOLERANCE] #3279658
01/01/25 12:46 PM
01/01/25 12:46 PM
Joined: Jan 2003
Posts: 4,395
Morrow, OH
markz528 Offline
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So you are running a single -8 from the tank to the pump? That won't work. And don't use 2 -8s to the pump. Use at least a single -10. And make sure that pump inlet is below the sump outlet. Otherwise you do risk pump cavitation.


67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......
Re: Loss of fuel pressure [Re: markz528] #3279687
01/01/25 01:24 PM
01/01/25 01:24 PM
Joined: Aug 2003
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Madison Wi
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Originally Posted by markz528
So you are running a single -8 from the tank to the pump? That won't work. And don't use 2 -8s to the pump. Use at least a single -10. And make sure that pump inlet is below the sump outlet. Otherwise you do risk pump cavitation.


This is the only pic I have at the moment. The sump only has 1/2 ports. Currently have a single 1/2 line/filter running into the pump. Here you can see the pump is just above the sump. I don't think I can get -10 coming out of the sump. I can drop the pump some to make it below the sump fittings

IMG_20241110_102830327~3.jpg

I used to care but....... things have changed
Re: Loss of fuel pressure [Re: NTOLERANCE] #3279714
01/01/25 02:10 PM
01/01/25 02:10 PM
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Morrow, OH
markz528 Offline
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So would like the pump just a little lower, but if you keep your tank relatively full it should be ok as the fuel level is above the pump inlet. But that line needs to go. Best case would be a -12 but needs to be at least -10.

When I sent my pump back to BG after it started not flowing, they said it showed signs of pretty significant cavitation. Did not show cavitation prior to the repair. I had been feeding it with 2 -8s and they told me to feed it with a single -10. Today I run twice the hp I did back then and feed the BG400 with a -12 and a BG filter before the pump. Has a -10 return line and I have zero fuel pressure issues.


67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......
Re: Loss of fuel pressure [Re: markz528] #3279715
01/01/25 02:12 PM
01/01/25 02:12 PM
Joined: Jan 2003
Posts: 4,395
Morrow, OH
markz528 Offline
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Also when I rebuilt the BG400 last year or so, it showed no signs of cavitation after many years of service.


67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......
Re: Loss of fuel pressure [Re: NTOLERANCE] #3279717
01/01/25 02:22 PM
01/01/25 02:22 PM
Joined: Jan 2003
Posts: 4,395
Morrow, OH
markz528 Offline
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Originally Posted by NTOLERANCE
The sump only has 1/2 ports.


What kind of 1/2" ports? NPT?


67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......
Re: Loss of fuel pressure [Re: NTOLERANCE] #3279753
01/01/25 03:44 PM
01/01/25 03:44 PM
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I was told years ago that those BG fuel pumps were designed for drag racing only, not for the street.
They said to use their 220 street pump kit for street cars scope
I ended buying a 275 Magnafuel pump and later one of their 300 pumps up scope twocents


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Loss of fuel pressure [Re: markz528] #3279815
01/01/25 07:54 PM
01/01/25 07:54 PM
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Madison Wi
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Originally Posted by markz528
Originally Posted by NTOLERANCE
The sump only has 1/2 ports.


What kind of 1/2" ports? NPT?


I believe so. It's been awhile and I'm not near the car at the moment

I can run a fitting to move it from 1/2 to -10.


I used to care but....... things have changed
Re: Loss of fuel pressure [Re: NTOLERANCE] #3279819
01/01/25 08:15 PM
01/01/25 08:15 PM
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Rittman Ohio
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I have a BG 280 pump I have on the bench that may go onto my Savoy this year. I have been doing some research on this pump and one of the things I have read was they were not designed for a return style system. I plumped in a bypass on the outlet to go straight to the cell from the pump. I agree with Mark on the inlet size I have mine planned out with a -10 line from the sump to the filter and pump. That pump should have -10 straight threads with O-ring fittings. On my bypass deal if it drops pressure I will just cap it off.

Gus beer


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Re: Loss of fuel pressure [Re: NTOLERANCE] #3279837
01/01/25 09:44 PM
01/01/25 09:44 PM
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Originally Posted by NTOLERANCE
Looking for some suggestions here
My gauge isnt great but it's new and currently accurate. ....
Once the fuel pressure drops to zero in the vid, I shut the pump off then back on and the fuel pressure comes back.



https://youtu.be/CR9SMVem7T4?si=5GneXC8UN8ZKau8K


I'm only seeing about 3.5 psi at the beginning of that pull , if your gauge is accurate isn't that kinda low , pressure is a resistance to flow so if you have 4 bowls calling for fuel all at the same time and only 3.5 psi ????

I might be wrong , but just an observation ....


Mainstream Media is the new Pravda
Re: Loss of fuel pressure [Re: JohnRR] #3279838
01/01/25 10:00 PM
01/01/25 10:00 PM
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Madison Wi
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Originally Posted by JohnRR
Originally Posted by NTOLERANCE
Looking for some suggestions here
My gauge isnt great but it's new and currently accurate. ....
Once the fuel pressure drops to zero in the vid, I shut the pump off then back on and the fuel pressure comes back.



https://youtu.be/CR9SMVem7T4?si=5GneXC8UN8ZKau8K


I'm only seeing about 3.5 psi at the beginning of that pull , if your gauge is accurate isn't that kinda low , pressure is a resistance to flow so if you have 4 bowls calling for fuel all at the same time and only 3.5 psi ????

I might be wrong , but just an observation ....


I set the pressure at 6 psi idle. I just put that gage on, it didn't have one before and I just got the car running this fall. I was cautious about going higher than 6 but maybe I need more. When I switched the pump back on it went back up to 6.


I used to care but....... things have changed
Re: Loss of fuel pressure [Re: NTOLERANCE] #3279844
01/01/25 10:24 PM
01/01/25 10:24 PM
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I use to set my fuel regulators up for 8.5 to 9.0 lbs. of pressure with the motor idling, someone who I trusted said your better off to set them at 5.0 to 5.5 lbs. of pressure to insure a good flow of liquid gasoline into the float bowls instead of using above 6.0 lbs. that makes the gas aerate with a lot of air mixed into the flow to the fuel bowls work wrench scope
He also said to disconnect one fuel line and set the fuel pressure with that one hose flowing into a bucket at 5.0 up to 5.5 lbs. of pressure flowing, that did make the car faster a tiny bit.
Fuel volume and fuel pressure are two distinctly different subjects, adequate volume flow being the key to going fast and not hurting parts.
If you can't jet the carb. /carbs. up enough to slow the car down by being too rich you don't have enough fuel volume work wrench scope twocents


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Loss of fuel pressure [Re: Cab_Burge] #3279887
01/02/25 08:52 AM
01/02/25 08:52 AM
Joined: Jan 2003
Posts: 75,418
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Originally Posted by Cab_Burge

He also said to disconnect one fuel line and set the fuel pressure with that one hose flowing into a bucket at 5.0 up to 5.5 lbs. of pressure flowing, that did make the car faster a tiny bit.


This ^^

I was trying to figure out what's the best way to do it when running 2 carbs after thinking how I had seen Finnegan and Frieberger set up fuel pressure for an add on nitrous system by putting the size fuel jet on the end for the supply line and running it into a bucket and adjusting the regulator . Maybe you could do the same by putting a jet the size of the needle valve, but you have 4 needle valves going at one time so maybe just running an open supply line would get you close enough while the other is dead headed to full fuel bowls ?


Mainstream Media is the new Pravda
Re: Loss of fuel pressure [Re: JohnRR] #3279937
01/02/25 11:41 AM
01/02/25 11:41 AM
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Try setting it with one outlet flowing into the bucket and then watch the pressure in high gear at WOT to see if it drops a lot or not work scope wrench


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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