Fuel Delivery Issue

[LGustin]

I picked up my square body yesterday from the fab/performance shop. When I flipped the switch to turn the fuel pump on I heard something like a grinding noise. The guy that worked on the truck told me it was the fuel pressure regulator. I went a head and trailered her home and when I tried to take it for a test drive it acted like it was starving for fuel. One of the things they did at the shop was replace all of the old rubber fuel and trans lines with braided stainless. Here is what I have...
Holley 12-1800 fuel pump - both sides of the pump are wired direct
Aeromotive boost reference fuel pressure regulator set at 8psi at idle
Holley filter after pump
Supply line - #10 stainless braid line
Fuel log line - #10 stainless braid line
Return line - #8 stainless braid line

Truck has been at the shop since August last year, no issues with fuel system before going to the shop. All of the fuel system is the same as before other than the new fuel line. Today I started looking for the root cause, removed fuel lines and blew through them with air compressor. Only one side of the pump was wired up so I wired in the secondary side. The filter had a few specks of trash but not enough to slow flow. I blew everything out and cleaned it up and reinstalled everything. Poured in some fuel and flipped the switch, sounded normal (fuel pump whine) until fuel reached the regulator and then noise started again. It sounds like the regulator is cavitating or pulsing/grinding. Its hard to describe but I dont like it. Could the cause be a failing fuel pump or pressure regulator? The regulator is less than a year old, the pump older. Any suggestions on what I should look for or try?

 

[Snoots]

Could be some trash in the regulator.

 

[LGustin]

Could be some trash in the regulator.

I will pull it tomorrow and clean it real good.

 

[LGustin]

Going to order a fuel pump today. Looking at Magnafuel 500 or Holley 12-1600. I looked on Holley's website to see if they offer a rebuild kit for the fuel pump thats in the truck now and did not see anything nor did I find anything about rebuilding them on the web. Seems like a miss for Holley to not make them serviceable. Oh well, I just want to get her back up and running.

 

[Honky Kong jr]

I’d wire the 2nd stage of that pump to be controlled by a relay triggered by a boost reference sensor, not direct. But thats me. Or get a fuel controller that will do it all for you 1st stage, 2nd stage and by boost. The run the pumps slower at idle so as to not heat the fuel. Sounds like your killing the regulator as it try’s to manage all that fuel. Just my .02

 

[LGustin]

I’d wire the 2nd stage of that pump to be controlled by a relay triggered by a boost reference sensor, not direct. But thats me. Or get a fuel controller that will do it all for you 1st stage, 2nd stage and by boost. The run the pumps slower at idle so as to not heat the fuel. Sounds like your killing the regulator as it try’s to manage all that fuel. Just my .02

Yep I agree thats how it should be wired for long term use and longevity. I wired it direct when I was trying to isolate the root cause of the noise at the regulator AND the issue of the truck not wanting to run. So this is what I know now...
Bypass is working, I have fuel returning to the tank. I disconnected bypass line at regulator and ran short hose to a can to see if the AN8 line was too restrictive. The hammering is still occurring. I pulled the regulator and made sure it was clean. I will put it all back together tomorrow. A buddy has a Magnafuel 500 that I can borrow to see if the Holley is failing and not pumping enough fuel to make the regulator work properly. So far thats what I know and still think its a pump issue.

 

[RustyPile]

................ So this is what I know now...
Bypass is working, I have fuel returning to the tank. I disconnected bypass line at regulator and ran short hose to a can to see if the AN8 line was too restrictive. The hammering is still occurring. I pulled the regulator and made sure it was clean. I will put it all back together tomorrow. A buddy has a Magnafuel 500 that I can borrow to see if the Holley is failing and not pumping enough fuel to make the regulator work properly. So far thats what I know and still think its a pump issue.

Your pump is rated at 200 GPH.. Have you conducted a flow test?? Your pump should deliver 3 1/3 gallons in one minute or less.. Will yours do that?? If not, the pump is bad..