Tech Tips

1. MPI kit installation tips
2. HESMIL Diagnostic Codes
3. Try our bulletin board
4. Instructions for using the HESEZCAM tool
5. Fuel Pump / Regulator installation
6. Fuel Pressure Regulator Eliminator Plug
7. Water pump torque specs
8. Jeep 2.5 & 4.0L Throttle Body Spacers

1. MPI kit installation tips
   

   CLICK HERE to download MPI Kit instructions and Installation tips.

    

2. HESMIL Diagnostic Codes
   
   CLICK HERE to download the check engine "MIL" diagnostic codes.

3. Try our bulletin board
   
   If you have an issue or need help with a subject not found here, try visiting our bulletin board to view previous discussions or to post a question.

4. Instructions for using the HESEZCAM tool
   Click here to download the HESEZCAM instructions directly from the products page.

5. Fuel Pump / Regulator installation
   CLICK HERE to download installation instructions.

6. Fuel Pressure Regulator Eliminator Plug
   

   The fuel pressure regulator plug is designed to be used with our rear mounted fuel regulator / fuel pump kit (Part # HESRMFPR1) where the stock regulator is eliminated from the fuel rail.
   CAUTION: DO NOT PERFORM THIS PROCEDURE ON A HOT ENGINE!
   Relieve the fuel pressure from the rail using a fuel pressure gauge with a bleed off valve or other suitable tool. Use caution as the fuel is under high pressure and the appropriate safety precautions should be taken. (ie: safety glasses etc.)
   Remove the fuel pressure regulator hold down clamp from the fuel rail. With a twisting motion remove the fuel pressure regulator, being cautious to make sure the old o-rings are also removed.Install the new o-rings into the fuel rail. This is simple as they will only seat in their respective grooves.
   Spray the o-rings with a silicone based or similar type lubricant to help ease the installation of the plug into the rail. With a twisting motion seat the plug into the fuel rail.
   Install the hold down clamp.
   Cycle the ignition switch to pressurize the fuel rail and check for leaks.
   You may either remove the stock fuel return line from the rail and cap the nipple or simply leave it attached.

7. Water pump torque specs
   

   For vehicle years 1997 and earlier, use 22.0 foot lbs. of torque. For all vehicles 1998 and later, use 17.0 foot pounds of torque.

8. Jeep 2.5 & 4.0L Throttle Body Spacers
   

   Remove the four bolts retaining the throttle body to the intake manifold. Remove and discard the throttle body gasket. Install the spacer (HESCO logo right side up) and gaskets, installing one gasket between the manifold and spacer and one between the throttle body and the spacer. Use the (4) 55mm cap screws and (4) washers to install the throttle body. Torque the bolts to 10-12 inch pounds. Remove the bolts retaining the throttle cable bracket to the manifold. Some Jeeps have two while earlier models will have three bolts. Place the black spacers beneath the bracket and install the 50mm bolts and flat washers. These also torque to 10-12 inch pounds. Dyno testing showed an 11 hp. Gain with an open air filter system. The typical power range differs with engine configuration.