ORS 3.4L Conversion Harness, for 3VZ-E and 22R-E Vehicles

(5 customer reviews)




Please see the ‘notice’ and ‘core connectors’ information located below description before ordering.

The ORS Conversion Harness greatly simplifies the electrical portion of the 3.4L engine conversion.

The wiring is possibly the most complicated part of this conversion. The 5VZ-FE (3.4L) fuel injection system is entirely different from that of the older Toyotas. This means the 5VZ electronics will have to be in installed in your older Toyota in order to make this engine swap possible. Unfortunately, the electronic EFI components from your older Toyota 3VZ-E or 22R-E will be useless in this swap.

There are 3 primary parts of this OEM 5VZ fuel injection circuit. The first is the engine wiring harness. This is the harness that is primarily attached to the engine. This is sometimes called the injector harness. This harness connects the engine components such as the fuel injectors, ignition coils, air flow meter, etc. to the engine computer and the body harness.

The second part is the Engine Control Unit, or ECU. This is also called the Engine Control Module, or ECM. Sometimes it is just called the engine computer. This is the heart of the fuel injection system. This maze of solid state circuitry uses various input signals and outputs to control the engine.

The third part of the 5VZ electronic fuel injection circuit is the body harness. This is sometimes called the “dash” harness or the “main” harness. It stretches across the inside of the dashboard and sometimes into the engine bay. This harness is the largest harness in the vehicle and carries the majority of the vehicle’s circuits. About 40% of the 5VZ fuel injection’s wiring circuit is contained in this harness.

The engine wiring harness and ECU are easy to install in another vehicle when performing this swap, but the real challenge comes about when it’s time to take care of that last 40%. This is where ORS Conversion Harness comes in. Our conversion harness is designed to provide that last 40% of the 5VZ fuel injection wiring circuit. This harness connects directly to the 5VZ ECU and engine wiring harness; then plugs directly into your older Toyota. The original wiring in your older Toyota will not have to be torn apart or changed in order to accommodate this new engine. The ORS Conversion Harness will also include the necessary emissions equipment wiring for your application. Additionally, this harness is designed to accommodate your OEM gauges (tachometer will require some additional work during the install), speed sensor, reverse lights, 4×4 system and 4×4 indicator lamp. The installation is almost entirely plug-in with only a small amount of splicing required.

The alternative is to re-wire your entire vehicle with a newer body wiring harness. The ORS Conversion Wiring Harness is designed save you an enormous amount of time and potential trouble.

This product is built per order, please allow 1-2 weeks for order completion.

“Donor Vehicle” options refer to the engine harness application.

Notice when ordering: Please include the following information in the “Order Notes” box when placing your order:

From Donor Vehicle:

  • VIN, only if 100% certain of engine origin, OR-
  • Toyota ECU and engine harness part numbers (8966x-xxxxx & 82121-xxxxx)
  • Model Year
  • Model
  • 4WD or 2WD
  • Manual or Automatic Transmission

From Your Vehicle:

  • VIN
  • Year Model
  • Model
  • Original Engine
  • Manual or Automatic Transmission (originally)
  • Indicate specific transmission to be used in conversion
  • 4WD or 2WD
  • If using 3.0L version of Auto Transmission, indicate transfer case to be used
  • Suspension type (original or modified)
  • For 89-95 Truck, 90-95 4Runner, Indicate if ADD (Auto-Hub) system is in use

Core Connectors:
For some applications we will need core connectors from you. If your vehicle is an ’85-’90, we need two connectors. These are on the 22RE or 3VZ-E ENGINE harness, behind/near the ECU connectors. They are the 2 connectors that join the engine harness to the body/dash harness. Cut them from the ENGINE harness w/ 1-3″ of wire lead. Note, we will fill w/ new wire terminals. We will send a label for a small flat rate box through USPS.

5 reviews for ORS 3.4L Conversion Harness, for 3VZ-E and 22R-E Vehicles

  1. Alan

    I was very pleased in quality of the harness.
    It came with very detailed installation instructions.
    Easy to use and didn’t have one problem.
    Very worth getting it you want a factory looking motor wire harness swap.
    Good customer service.

    • Mike Caskey

      We appreciate the feedback and are glad the install went well!

  2. thomas

    worked great fired right up, the only thing i did different was reused some of the 4×4 and reverse light plugs to make it plug right in

  3. stevewike.sw

    The harness is very well made and is very close to a plug and play installation it requires a small amount techni al ability but overall it is an excellent product and I wouldn’t hesitate to recomend the ORS conversion harness to my friends or to use it again myself.

    The only negative comment I would make is the turnaround time was more than a week longer than was quoted and delayed the completion of my 4runner and caused me to have to camp in a campground with several thousand other people instead of going deep into the mountains to away from the masses. So allow plenty of time and add about 10 days to the turnaround time they give you to avoid disapointment.
    Overall good service, good product and most of all good people.

    • Mike Caskey

      We appreciate your kind words and are very glad your overall experience was good. We can get very busy during certain seasons and sometimes do miss our estimated time mark. Since our wire harnesses are uniquely built per order, it can be a real challenge for us to determine and meet deadlines. We will continue to strive for improvement in this area, and we greatly appreciate our customer’s patience along the way.

  4. Barry Gage

    I bought one of these harnesses and it worked perfect. It included the engine swap from a 99 fourrunner to 88 fourrunner and included front and rear locking diff and auto trans and everything worked perfect. I did have a bad ECU and the tech guys walked me through steps of checking it out. Ordered a used one off ebay by number they recommended and it started up first turn. These guys know what they are doing!!!

  5. davis.kaihe (verified owner)

    Awesome harness.Super easy to use.Pretty much a no brainer. Does take about a month to receive but its a custom made to order part and I didnt expect it to be in any quicker then it did.

    • Mike Caskey

      Thank you for your comment. We appreciate your business!

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