ORS 5VZ-FE Conversion Wiring Harness

(6 customer reviews)



It is important to read full product description before ordering:

NOTE: If using factory 3vz auto transmission please read the below info under “If using an original 3vz-based A340” detailing the need of a T-100 ECU

The 5VZ-FE (3.4L) fuel injection system is entirely different from that of the older Toyotas. This means the 5VZ-FE (5VZ) electronics and circuit will have to be installed in your older vehicle in order to make this engine swap possible. The Off Road Solutions 5VZ Conversion Wiring Harness will provide the donor vehicle engine and transmission control circuits in your older vehicle for use with the Toyota engine 5VZ computer and components.

From the factory, there are 2 primary parts of the OEM 5VZ fuel injection wiring 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 (ECU) and the body harness.

The second part of the 5VZ electronic fuel injection circuit is built into the body wiring, along with the rest of the vehicle’s circuits. The body wiring includes the “under-dash” harness, the engine-bay harness (including fuse box), and even the wiring to the rear. About 40% of the 5VZ fuel injection’s wiring circuit is contained in this harness.

We offer our 5VZ Conversion wiring in 2 main formats:

  • Our 5VZ Conversion Adapter Harness is designed for applications that have a used, good-condition, intact engine wire harness from the donor vehicle. Our Conversion Adapter Harness will connect directly to the engine wire harness and the ECU, and works along with the donor engine wire harness to fully complete the engine wiring circuit. Note: The Adapter Format of our conversion harness will not work with “JDM” engine wiring (from Japanese Domestic Market); our Engine wiring format is recommended with JDM donor engines. Once again, the Adapter version requires the use of donor engine wiring that is intact and in good condition; from a North-American-based donor vehicle.
  • Our 5VZ Conversion Engine Wire Harness completely replaces the engine wire harness while also providing the portion of donor engine circuit originally in the body wiring. This harness is a combination of an engine wire harness and an adapter harness and houses 100% of the 5VZ engine circuit in one all-new piece. It is intended for situations when the donor engine wiring is missing, cut or in poor condition; or when all-new wiring is desired. It also works well for JDM import engines since the JDM engine wiring is hard to use in a LHD application.

We also accommodate 2 main recipient vehicle types:

  • Our 22R-E/3VZ-E Vehicle option is for ’85-’95 Truck/4Runner and ’93-’94 T100 vehicles that originally had the 3.0L 3VZ-E engine or the fuel injected 22R-E. This version requires that the original body wiring and fuse box is still in place and will plug directly into the body wiring for a simple install. Very little splicing is required to install this version; it is nearly 100% plug-and-play. The original wiring in your older Toyota will not have to be torn apart, and this version will 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.
  • Our Stand-Alone version is designed for virtually any other vehicle. It works well with carbureted vehicles, other makes, and some race/custom vehicles. This version requires that the vehicle has at least a basic electrical system already in place. This basic system must include: start and ignition switch, charging, fuse/battery and gauge circuits. This will connect to the recipient vehicle through a few simple splices. Note that the Stand-Alone version includes a fuel pump power/control circuit. Note: if your vehicle has no wiring body wiring at all see our Monster Harness.

We offer 2 options regarding the transmission:

  • Manual Transmission: Use this option when using a manual transmission. This includes a case where the donor or recipient vehicle was originally auto and the engine setup will now be manual.
  • Automatic Transmission: Use this option when using a Toyota automatic transmission. This includes a case where the recipient was originally manual but is now being converted to an automatic transmission. Like the engine circuit, the transmission control circuit was originally split between the body and engine wiring. The Adapter format will include the portion of the transmission control circuit originally placed in the body wiring and the Engine Wire Harness format will include all-new transmission connections.

If using an original 3VZ-based A340 automatic transmission: the ORS harness will connect directly to the A340 sub-harness and connections, however, some recipient models will require the use of a late-3VZ (94-95) or 5VZ-donor park/nuetral switch (which is a simple and direct install). Additionally, a donor T100 ECU is required. If purchasing an ORS adapter-format conversion harness, the use of a 98 or older 5VZ-A/T engine wire harness is required for use with a T100-based ECU. We recommend inquiring about application compatibility (by email or phone) when using an engine harness and T100 ECU from different applications. If a 1998 or older engine wire harness is not available, we recommend the purchase of the ORS Engine-format Conversion Harness.

Donor vehicle pricing options are for the Adapter format and depend on the engine harness donor application.

7th Injector Add-on, ORS Engine Harness Format Only:
If there are plans to use the URD 7th-Injector Fuel-Upgrade kit w/ a TRD/Magnuson Supercharger this add-on would be a big help. The 7th Injector has a small sub-harness that requires several splice-connections into the engine wiring. This can be difficult to trace wires and make the connections and requires cutting into an engine harness. Our add-on is a simple connection into our engine harness for the 7th Injector sub-harness. These required 7th Injector splice-connections are built into the new ORS wiring and routed to an additional connector. This would allow you to take the additional provided pigtail, splice to the 7th Injector harness on the bench and simply plug it into our harness. This eliminates wire tracing and splicing into our new engine wiring. This upgrade also comes w/ a separate “lock-out” plug that allows our harness to be operated, in the meantime, without the 7th injector kit installed. This is a $105 upgrade.

This product is built per order, please allow 2-4 weeks for order completion. This time can vary by season, if completion time is crucial, please contact ORS before ordering.

Notice when ordering: Please include the following information in the “Order Notes” box or a separate email when placing your order. If sending a separate email be sure the name on the order will be obvious.

From Donor Vehicle:

  • VIN, only if 100% certain of engine origin, OR part numbers requested below
  • Toyota ECU part number (8966x-xxxxx)
  • For Adapter Harness version: Toyota engine harness part number (82121-xxxxx), this is found on a paper tag near the ECU connections.
  • Model Year
  • Model
  • 4WD or 2WD
  • Manual or Automatic Transmission

From Your Vehicle:

  • For 3VZ-E/22R-E type: VIN – please email image of VIN tag (driverside door jam) with 1990 and older models
  • Year Model
  • Model
  • Original Engine
  • Manual or Automatic Transmission (originally)
  • Indicate specific transmission to be used in conversion
  • Shifter to be used (for A/T models)
  • 4WD or 2WD
  • If 4×4, indicate transfer case application, original to transmission or changed
  • Front suspension type (original or modified)
  • For 89-95 Truck, 90-95 4Runner, Indicate if ADD (Auto-Hub) system is in use
  • Will you be swapping the battery to the left hand side of the engine bay
  • OEM (original-type) tachometer in use?
  • Plans to add a supercharger with 7th-Injector fuel kit?
  • For Stand-Alone: ECU Location
  • For Stand-Alone: Fuel pump location
  • For Stand-Alone: speedometer type

Core Connectors for 22R-E/3VZ-E recipient type:
For some applications we will need a core connector from your vehicle. If your vehicle is an ’85-’90, we need one core connector. It is found on the 22R-E or 3VZ-E ENGINE harness, near the ECU connectors. There are the 2 connectors that join the engine harness to the body/dash harness, one of these is needed. Once an order is placed, we will send a picture of the connector needed and a label file (for print) that can be used to send the core connector in a USPS Small Flat Rate Box. Cut the connector needed from the ENGINE harness w/ 1-3″ of wire lead. Note: we will fill the core connector w/ new wire terminals.

Installation Instructions

6 reviews for ORS 5VZ-FE Conversion Wiring Harness

  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!

  6. Kody Maus (verified owner)

    Do yourself a favor and save yourself a ton of time with this harness. I ordered the full harness which I would do 100 times over. These guys are very good at what they do, very detailed instructions and really makes your swap a breeze.

    Granted I’ve got a little more experience with this type of stuff than the average person, but it took me about an hour to get the swap in and running with this harness, but even still with the amount of detail that goes into this harness and instructions, it wouldn’t even take that long for someone who’s never done anything like this before.

    Customer service is insanely good, fast response and accurate lead times. ORS crew keep up the good work!

    • Mike Caskey

      We greatly appreciate your input, it means a lot to us. We work hard to create useful products and provide good product support. We are glad your wire harness was helpful!

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