Mopar Performance 4.2L MPI Conversion Fuel-Pressure Filter/Regulator

[William H]

I recently purchased a 85 CJ7 equipped with the updated 4.2L MPI conversion with TJ style single fuel hose.

I am trying to locate a replacement Fuel-Pressure Filter/Regulator as pictured below. As you know, this unit mounts on the outside of the fuel tank. Actually, my CJ has been upgraded with a 20G aftermarket fuel tank with a fuel pump/sender as shown in the picture by the previous owner.

 

When looking up the Mopar Performance part# (04798301) supplied in the documentation that was left by the previous owner, I find the unit shown below. This unit mounts into the top of a fuel tank pump/sender assembly.

 

Thanks for any help in locating a replacement fuel-pressure filter/regulator for my Mission Critical spare parts.

Edited November 25, 2016 by William H
Pictures didn't show up

[Moses Ludel]

William, you do have the later Mopar EFI kit, which is patterned after the TJ/XJ single rail fuel delivery design.  The externally mounted fuel pressure regulator/filter is one of the few parts in the system that does not look like an off-the-shelf Mopar component for a 1997-up 4.0L MPI Jeep TJ or XJ.

Look closely...The part you're seeking is actually an OEM filter regulator (1997-up type TJ). In your later system, there is a machined lower housing that provides a seal when the unit is mounted externally.  (The OEM mounting method, as you note, is into the fuel tank.)  

If you remove the lower aluminum machined housing from the top piece, you can confirm whether the actual filter/regulator is the same as a 1997-up TJ OEM type.  If so, that's the part number.  

Unless the filter/regulator is modified, this would be a simple case of installing a '97-up OEM filter/regulator into the custom lower housing.  Make sure the seal between parts is good.  If you need to replace the housing seal, be sure to use a gasoline resistant seal.

Note that HESCO provided the outsource parts for the Mopar EFI conversion kits.  They continue to offer replacement parts for your application of the EFI system.  Here is the link, you'll see the pressure regulator/filter listed, and like the one in your illustration, it is simply a Mopar OEM filter/regulator:

http://www.hesco.us/products/7577/mopar-mpi-kit-and-replacement-parts

Moses

 

[William H]

Moses, thanks for your rapid and very clear response.

I now understand that my external mounted fuel regulator assembly consists of two parts. The upper half is the OEM regulator for a 97-up TJ. The lower half is a machined adapter that emulates the fuel tank receiver on a 97-up TJ.

William

[Moses Ludel]

William...You've got it!  The pressure/regulator is an OEM replacement part.  Protect the machined lower/remote mount housing, that's the proprietary (custom) part.

Nice Jeep CJ there!  Share some pics of the Jeep and Mopar EFI conversion...Have a good holiday weekend!

Moses

[RareCJ8]

I thought the regulator is mounted on the fuel rail?

 

[William H]

Yes, some of them do. If you go to Auto Zone, the only one that comes up is the one that mounts on the fuel rail. Not sure which year models have what. I have never owned a jeep newer that a CJ, maybe somebody with newer models can break it down better.

William

[Moses Ludel]

The 1991-95/96 original equipment Jeep Mopar MPI systems use a 4.0L two-rail EFI with a return line to the fuel tank.  The 1997-up models all use the tank regulator and a single rail EFI/MPI system.  The regulator pictured above is the 1997-up OE regulator with a custom body.  On the OE application, the regulator mounts atop the fuel module at the tank.  The break year is 1996/97 for these two systems.

Mopar's EFI Conversion was originally patterned after a 1994-95 Jeep YJ Wrangler 4.0L system, which is two-rail EFI with the return line to tank.  These kits use a universal type external electric fuel pump with the correct pressure for this system.  The pump and clamp mounts near the tank on the frame rail.  The later Mopar EFI Conversion uses a single rail 1997-up type TJ Wrangler system with no regulator at the engine fuel rail.  Here, the pressure regulator is at the fuel tank (OE) or nearby the tank as the custom regulator in the Mopar EFI Conversion Kit.  The current Mopar EFI kit is single rail.

The early kit's two-rail system has the pressure regulator at the fuel rail and a distinct return line to the fuel tank that must be unrestricted.  The later single rail systems do not have the return line but instead have a device at the rail that looks similar to the earlier pressure regulator.  This is not a regulator, it's a fuel pressure damper.

Moses