Mopar MPFI Canister Connections

[Mjmcovol]

First, I'm not sure what I would do without your books.  I'm a newbie mechanic restoring my own 82 CJ7.  I have your Jeep Rebuilder's Manual and I have searched many forums.  The complete MPFI kit came with my 82 CJ.  I'm lucky because the kit was worth more than I paid for the entire Jeep. With some help from a mechanic friend the install of the MPFI has been pretty straightforward. I still have some factory wiring issues (what I need to use, what I don't) but I'll go slow and steady and figure out.  

My question is mainly around what needs to be connected to the charcoal canister that came with the kit and where.  The "carb" port is sealed on my canister. So I have a larger vent looking port on the left just like the one below.  As this picture shows can I connect vent to fuel tank on this larger port?  What connects to the smaller black fitting on the top. Right now my single rail fuel pressure regulator is connected just to manifold vacuum.  Do I need to use the split fitting and connect this to the canister as well?  

I also have a connection that comes from the new air intake that I'm pretty sure goes to the canister.  My last question is do I need this line from the kit and and if so, where does it go?  I really have searched and found many photos and have your instruction from Jeep Restorers Bible and Mopar MPFI instructions but they only show one end.  I'm so new to this I need the connect this to this.  Thanks so much!

 

Michael

 

[Moses Ludel]

Welcome to the forums, Michael!  Your photos are helpful for solving your dilemma.  This canister comes with the Mopar EFI Conversion Kit and is a 1994-95 Jeep YJ Wrangler application.  

HESCO Jeep (http://www.hesco.us) has taken over the Mopar EFI Conversion Kit parts sales.  They know this system intimately, and at the HESCO site you will find download instructions/tips for your kit.  If you cannot get the download, contact HESCO for details, the tech line is familiar with the hookups for EVAP. 

If you have the later EFI kit with single rail system, what you think is the regulator at the rail is actually a fuel pressure damper.  The fuel pump, filter and custom bodied fuel pressure regulator (which incorporates a 1997-up TJ Wrangler fuel pressure regulator that normally mounts above the TJ fuel tank) should each be mounted as near the fuel tank as practical and safe (away from trail damage and any exhaust heat).  Note the routing of hoses from the air induction box to the valve cover for crankcase venting.  (The 4.0L engine does not use a PCV valve, it uses a fixed orifice CCV system.)  You may have the air intake hoses misrouted and should follow the PDF example for the YJ Wrangler 4.0L MPI engine.

As for the plastic pipe you illustrate, confirm whether this formed tube is the MAP signal from the intake manifold to MAP or the vacuum supply for the EVAP canister. You do need a manifold vacuum hose for manifold vacuum to the canister as illustrated in the 1994 YJ Wrangler PDFs below.  There is a description of EVAP canister operation in one of the PDFs, which should help.

Each of the ports at the canister should be marked, otherwise refer to the PDF diagrams below. Here are vacuum schematics, including the EVAP circuits, for your CJ chassis and also for a 1994 4.0L MPI YJ Wrangler.  This will help you sort out the vacuum routing and venting.  Note the 1994 letter legend describing the routing for each pipe on the canister and also the schematic with the 4.0L engine's EVAP hose routing:

1981-86 Jeep CJ 4.2L Vacuum Circuits.pdf

1994 YJ Wrangler EVAP Canister and Hoses.pdf

1994 Jeep YJ Wrangler 4.0L EVAP Routing.pdf

HESCO MPI information (http://www.hesco.us/techtips.asp#techtips92051) should be able to clarify whether your kit is complete.  If the wiring harness was included, you only have a half-dozen wires to connect with your OEM Jeep CJ chassis harnesses.  This is a well conceived "bolt-on" kit and installer friendly if you have all the pieces.  HESCO also has a friendly tech support line and parts listings that will clarify your system and its pieces.

Let us know how this unfolds...RareCJ8 and 60Bubba also run your basic system and could help in this discussion.

Moses