Jeep Fuel Injection Kits

 The article below is about various fuel injection kits that we have had direct experience with in 1997. The intent of the article is not to discredit any product nor is it to "push" any other product. We simply want to share with others what we have learned through experience (and cost) so you may make an intelligent selection. If you have used other kits please let us know. We would love to detail more options. This list in no way covers all available kits. You will find many companies offering fuel injection kits (primarily for Chevy motors) in the various performance magazines. These pages present the personal opinions of the authors and in no way reflect official endorsement or condemnation of any of the products mentioned.

Index

• Fuel Injection for the 4.2 liter 6 cylinder

• Fuel Injection for the AMC V-8

• Fuel Injection for the Chevy V-8

• What do we believe?

• Why do we believe it?

• Where does that leave you?

• Tips for successful use of fuel injections

• DirtFirst! Technical Page

Check out the product reviews:

• ***** Holley Pro-Jection for the AMC V8 *****

• ***** Electromotive JFI kit for the AMC 258 I-6 *****

JFI
• This kit is a 50 state legal throttle body retrofit. We have a lot of experience with this product. The kit installs easily, (took me about 12 hours), and really cleans up the engine bay and smoothes out the motor. The engine wiring and vacuum system are greatly simplified.
• The stalling and flooding associated with carburetors and hard-core off-roading is gone. Cold start problems are gone. Low end torque is improved (a little). Horsepower is not increased because the throttle body bores are too small.  The fuel economy on the hwy improves a little. Off road fuel economy improves dramatically.
• The computer is failure prone. The sensors and wiring are failure prone. Three of us ran this kit in the past and none of us use it today. My motor burned up two times because the coolant temperature sensor failed. Several people in my 4x4 club are having similar problems. When it runs it is great, however part failures can be very costly and frequent.

Clifford
• We have no experience with this kit. It is not 50 state smog legal, but they have been around for a long time.
   
Holley
• Holley builds throttle bodies for GM and others. This kit is based on those throttle bodies and Holley's own electronics. We have no direct experience with this kit. However, it is similar to the kit for AMC V8's so see article on Holley Pro-Jection for what you might expect. It is not 50 state smog legal.
  • Horsepower and torque are greatly improved.
  • Vacuum system is simplified
     
  Chrysler
• The multi port kit offered by Jeep is 50 state smog legal. It employs the fuel injection system, computer, wiring harness, and intake from the 1995 4.0 liter motor. Although fairly expensive, this is the kit we would use.
• It uses factory parts for reliability and dependability.
• it can be serviced anywhere.
• There have been many inquiries about this product, so here is a source for more information.  
  Magazine article, 4 Wheel Drive & Sport Utilty, September 1997 issue. Page 68, - Injection Connection.
  
  

MPI torque = 256.8 ft-lbs @ 1600 rpm

From the article:
"The first thing we noticed was that the Jeep felt and sounded like it had a new motor. The seat-of-the-pants sensation made the I-six we new was under the hood feel more like a V-8."

They really liked it. If you do this install, please write /e-mail us about it.

Here is a link that offers the kit for sale. Looks the price has come down too! ($1650.00 + damper)
http://crowleyauto.com/crowley/moparperf.htm

Howell

• The kit offered by Howell is not 50 state smog legal (at this time). It employs the throttle body, computer and wiring harness from a Chevy 4.3 liter motor.
• When this kit becomes smog legal we would use it.
  (update 1999 - the kit is now claimed to be 50 state legal, check it out!)
• It uses dependable factory parts.

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Holley
• Holley builds throttle bodies for GM and others. This kit is based on those throttle bodies and Holley's own electronics. We have much direct experience with this kit. See article on Holley Pro-Jection for what you might expect.
• Horsepower and torque are greatly improved.
• Vacuum system is simplified.
• It is not 50 state smog legal at this time

Turbo City
• The kit offered by Howell is not 50 state smog legal (at this time). It employs the throttle body, computer and wiring harness from a Chevy V-8 motor.
• When this kit becomes smog legal we would use it.
• It uses dependable factory parts with a reprogrammed ROM Chip.

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Holley

Holley builds throttle bodies for GM and others. This kit is based on those throttle bodies and Holley's own electronics. We have no direct experience with this kit. However, it is similar to the kit for AMC V8's so see article on Holley Pro-Jection for what you might expect.

• Horsepower and torque are greatly improved.
• Vacuum system is simplified It is not 50 state
  smog legal at this time

Howell

The kit offered by Howell can be made 50 state smog legal. It employs the throttle body, computer and wiring harness from a Chevy V-8 motor.
We would use it.
It uses dependable factory parts with a reprogrammed ROM Chip.

Turbo City

We are not familiar with their kit but they advertise 50 state smog legal.

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What do we believe?

1. We believe in using factory parts whenever and wherever possible.
2. We believe in using parts that will meet 50 state smog laws and actually help significantly reduce vehicular emissions.

Why do we believe it?

1. The factory spent more money on development of a single component than most aftermarket companies will ever make on a product. The factories make sure that their products "fail - safe" and let you limp home with out destroying your engine.
2. Smog laws are here to stay. We need cleaner air. We can help by improving the efficiency of our vehicles through legal means. A jeep equipped with a modern motor (i.e.: late LT1) will produce over 300 horsepower, make over 300 ft/lbs of torque and still turn in fuel economy numbers in the upper teens (with 35" tires). It can (if approved) meet 50 state smog laws, emit far less pollutants and consume much less fuel. Yes, you can simultaneously improve performance and clean up the air.

Where does that leave you?

1. For Chevy engines: Several companies offer smog legal retrofit kits for the Chevy motor systems. They are found in most hot-rod, Chevy magazines and 4x4 magazines. Get one based on "Chevy" parts and make sure it is 50 state legal. Ask for an EO number.
2. For AMC Jeep 4.2 engines: Several companies offer smog legal retrofit kits for the old 4.2 motor systems. JFI and Jeep are the most common. Get one based on "JEEP" parts and make sure it is 50 state legal. Ask for an EO number.
3. For AMC Jeep V-8 engines: Several companies offer non-smog legal retrofit kits. Get one based on "Chevy" parts. Be aware that you may not be smog legal.

Tips

• hook up all sensors, etc. (beware of kits which disable park. neutral switches, etc.) The computers use all of the sensors and it will run better with them installed and working.
• make sure the system is closed loop
• use high pressure fuel injection type fuel line
• use good quality hose clamps (double, clamps for more security)
• use a free flow exhaust system and catalytic converter. You can make well over 400 hp with a good exhaust system.
• look into a smog-legal retrofit using a late model fuel injected engine. (check your local laws - FIRST!) Get the book on TPI/TBI engine swaps by JTR. Summit racing carries it. Read it first!!!!!
• ask about parts lists and parts availability
• do not use silicon form-a-gasket anywhere near the air intake system, unless it states on the tube - "sensor-safe".  It will destroy your O2 sensor if you do.
• be very gentle with mass air-flow sensors and don't poke anything into them or you will be looking for a new one.
• Use a fuel injection - ready tank with an in-tank fuel pump because the fuel pump will be protected from trail damage.  It will be cooled by the fuel in the tank and pretty immune to vapor lock. Fuel delivery will be more reliable with the fuel pickup point in the tank.
• Get a good book on fuel injection and read it several times. It will help you understand what you need.

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