Regulator Return Routing

[Oldstock14]

I’m putting in a Holley blue, and need to install the regulator. While the regulator routing to the filter head is self explanatory, I’m having some trouble finding a way to route the return from the regulator. I’ve read that teeing into the existing factory return system can cause all sorts of problems because it pressurizes the system. Curious how any of you that run a regulator to control pressure do it.

 

[IDIBRONCO]

Good news/bad news. You don't need a returning regulator with a Holley blue or red. Just with a Holley black.

 

[KansasIDI]

I’m putting in a Holley blue, and need to install the regulator. While the regulator routing to the filter head is self explanatory, I’m having some trouble finding a way to route the return from the regulator. I’ve read that teeing into the existing factory return system can cause all sorts of problems because it pressurizes the system. Curious how any of you that run a regulator to control pressure do it.

I think the R&D kits route it back into the inlet right in front of the e pump

 

[Oldstock14]

Good news/bad news. You don't need a returning regulator with a Holley blue or red. Just with a Holley black.

My Holley blue was pushing 13 PSI and through my timing off so bad, I didn’t even want to run the truck lol. It was that rough. I don’t have a timing setup so I can’t time it for 13 PSI, I need to pull down the PSI and I’ll fine tune it once I finally get a timing set up.

 

[Oldstock14]

I think the R&D kits route it back into the inlet right in front of the e pump

Hadn’t thought of that. One guy in a FB group said he routed it back to the filler neck right so I was going to go that route but I like the idea of running only a foot or so of line back to the inlet a lot more.

 

[asmith]

My Holley blue was pushing 13 PSI and through my timing off so bad, I didn’t even want to run the truck lol. It was that rough. I don’t have a timing setup so I can’t time it for 13 PSI, I need to pull down the PSI and I’ll fine tune it once I finally get a timing set up.

What @IDIBRONCO was saying is with the Holley blue you dont need to return the regulator. It can just be a deadhead. That is the way mine is right now. If you want to return it you can, but it is not necessary with the Holley Blue or Red.

 

[Oldstock14]

What @IDIBRONCO was saying is with the Holley blue you dont need to return the regulator. It can just be a deadhead. That is the way mine is right now. If you want to return it you can, but it is not necessary with the Holley Blue or Red.

That wouldn’t be bad for the pump? I know we’re talking pretty low psi and I actually debated deadheading it earlier but decided against it cuz I was convinced it wouldn’t be good for the pump.

 

[asmith]

Not according to Holley. That is just fine with the red or Blue. The Black needs a return line for the regulator.

 

[IDIBRONCO]

My Holley blue was pushing 13 PSI and through my timing off so bad, I didn’t even want to run the truck lol. It was that rough. I don’t have a timing setup so I can’t time it for 13 PSI, I need to pull down the PSI and I’ll fine tune it once I finally get a timing set up.

Not according to Holley. That is just fine with the red or Blue. The Black needs a return line for the regulator.

This right here. You can save yourself some trouble. The bad news part, Oldstock, is that you've already bought a returning regulator, or so it sounds.

 

[IDIBRONCO]

That wouldn’t be bad for the pump? I know we’re talking pretty low psi and I actually debated deadheading it earlier but decided against it cuz I was convinced it wouldn’t be good for the pump.

It's not so much the pressure as it is the volume of the black Vs. the red and blue. I would also recommend installing an aftermarket fuel pressure gauge to keep an eye on the pump. If the pressure starts dropping for some reason, you'll be aware of it before you're stranded alongside the road.

 

[Oldstock14]

Not according to Holley. That is just fine with the red or Blue. The Black needs a return line for the regulator.

This right here. You can save yourself some trouble. The bad news part, Oldstock, is that you've already bought a returning regulator, or so it sounds.

I actually bought this pump and regulator second hand new in box for cheap but it came with no documents, so this just saves me labor and I can take some fittings back to the hardware store for some money back. Fuel gauge is already installed up under the hood until I can get one installed in the cab. Thanks for the info and help guys.

 

[Lumberjackchuck]

Do you still have a fuel tank selector valve?

If you don’t, I think you might be able to tee into the return somewhere near the tank and it shouldn’t pressurize the return too much.

I tried this out myself tee’ing into the return before the selector valve and it pressurized the return wayyy too much. I had a geyser of fuel shooting out of return caps. The orifice diameter in the fuel tank selector valve is too small and causes too much restriction and pressure buildup in the return system to facilitate the flow rate of the regulator return. If you want to tee into the return, you gotta get rid of that valve.

For now I routed my regulator return to the supply side of the pump but that also has its down sides since you can have air constantly circulating in the system. It does make it difficult to purge air out.

Eventually I will convert to a single 38 gallon rear tank and plumb my return directly back to the tank. For reference, in my set up I’m using a Holley black. I’m not sure how much flow you get in the regulator return with the blue.

 

[MtnHaul]

I had asked the owner of Classic Diesel Designs the same question and he said that for a Mr Gasket 105P, which is basically the same spec as Holley Blue, that the regulated return was not necessary and just to deadhead the fuel and use a regular regulator. But yeah I had the same concern/thought about the deadhead pressure being bad for the pump.

 

[Nero]

Depends on the style of pump. If its designed to be dead headed it won't hurt it. Hard to say though

 

[franklin2]

Depends on the style of pump. If its designed to be dead headed it won't hurt it. Hard to say though

On the pumps that are designed for it they have a spring and a return passage inside the pump. So the fuel just recirculates around inside the pump once the rated output pressure is reached.