The Stovebolt Site Forums The Shop Area The HiPo Shop In need of an education.

I have a sniper II trying to go in due to not liking the gremlins of the sniper I.

The II has a external fuel pressure regulator. The directions show it being installed on the return line. Makes sense cause the unit needs 60 lbs.

I'm trying to find the correct fittings I have had both Holley and fitting place telling me to put the regulator on the inlet side of unit? This makes no sense to me.

What am I missing? If it's on the inlet side the psi is between the pump and regulator. If it's on the return side the pressure is backed up into unit which needs it?

I think you're right. If you put the regulator on the inlet of the unit, there won't be enough pressure for it to work correctly. The regulator works like a relief valve. If the pressure is above the setting, the valve opens to let some pressure out.

I have no experience at all with aftermarket fuel injection systems, (and I have no desire whatsoever to learn about them) but all the OEM systems I've worked with had a boost pump in or near the fuel tank, and a pressure regulator between the fuel rail and a return line to the tank. Some of them were vacuum modulated so a drop in manifold vacuum resulted in an increase in fuel pressure. That's been the basic design of factory FI systems since the mid-1970s.

How many ports does the regulator have? Do you havr a picture?

The regulator on one of my other rigs is set up where it is on the inlet side of the throttle body. The regulator itself has the return line, and the outlet side of the throttle body is blocked off.

I know the Sniper 1 had that layout listed as an option in the manual.

What am I missing?

You are missing the fact that Holley makes the Sniper, You are missing asking them this question........ "Why do the instructions say one thnig and the online/phone tech says another?"

CLICK

Older snipers had built in reg. Newer do not. It definitely goes on the return as the instructions say.

Ferris,

I am assuming you have the 12-886 or 12-882 regulator that Holley recommends. If not, let uss know.

Those are bypass regulators, so they can be installed as a three hose setup on the inlet port of the throttle body (with the outlet port blocked) OR as a two-hose setup on the outlet side

Both options are valid, you just have to plumb it appropriately for the configuration you want.

Others: Consider this your warning that you are edging over the line on being unhelpful/mocking. The mod team will respond more harshly if this continues. Some posts have already been removed.

The diagrams have different regulators shown/PN's, so kind of confusing and is why I recommend sticking with the instructions and not wory about it. Instructins say use 886 or 882 on the return. We are supplying TMI for a TBI

SOME so called instructions show carburetors. Diagram just says bypass regulator, no PN.......don't mention EFI plumbing.

Some showing same diagram for Holley 12-803BP. Low pressure adjustable regulator plumbing..... and talk about needle and seat.

Let me try and give more information.....

The regulator has three ports. Two inputs and one output. The output form the bottom leg of the T of the three ports.

The outlet is the bottom of the T.

This is an inhouse regulator to the engine manufacturer, and not Holley, however the engine manufacturer is not advertising it is there inhouse regulator.

I have been working with Holley. They are not interested in getting my non Holley unit to work with the Holley system. They have also begun instructing me to put the regulator in front of the sniper which I repeatedly said made no sense and contradicts the instructions. They have little to no response when I ask why is it different.

After speaking with efisystemspro, they explained this very well and slowly in order for me to get a decent understanding, and they gave me two options to plumb things. Have to thank Fibonachu as well. I was having a hard time understanding how it was going to maintain PSI.

Fibonachu's two diagrams are essentially the same. The ports on the side of the regulator are both on the high pressure side and the bottom port is the relief back to the tank. So the fuel rail to the injectors is on the high pressure side in both cases. You can use either piping diagram.

Based your description, it sounds like it is an equivalent regulator to the Holley units in the diagrams above.

Are you looking for more help/feedback on this? Or do you think you have it figures out with the help from efisystemspro?

Seems like everyone, including Holley, have regulator "plumbed" the same. I am wondering if Holley is just saying plumb the regulator "PHYSICALLY" on/at the front of the TB as shown in one diagram. As reported, it works at either "location". Maybe just a miscommunication?

The "physical" location is immaterial. It's the "HYDRAULIC" location that's critical. The fuel rail needs to be on the high pressure side of the regulator in any case.
Fibunachu's Figure 2 is equivalent to having the fuel rail on a tee with the regulator downstream of that. It's just that the tee is built into the regulator.

locking the thread. Ferris surely has his answer by now.