1998 Tacoma 5.3L Vortec (LS) Engine Swap Thread

OK, let's finish this.

I added a 2nd fuse block next to the first and used two more relays, one for the electric fan and another for the starter. The 2nd fuse block gets power from the 1st and I'm only using two fuses in the 2nd block for now, to protect the fan and starter circuits.


A fused 12 V wire (green) was wired to terminal 30 on the fan relay and terminal 87 was wired to the red wire on the electric fan. The black wire on the fan gets connected to chassis ground. The PCM will supply the (negative) or ground signal to turn on the fan relay, this gets wired to terminal 85 on the relay. Fused 12 v also needs to get wired to terminal 86 on the relay. When the PCM detects the engine coolant get above 200 F, the PCM grounds this connection and the relay turns on, turning on the electric fan.

 

If there's one thing GM can do right it is build a motor. It's everything else that seems to go bad on those trucks.

 

Fused 12 V power (green wire) is also supplied to terminal 30 on the starter relay. The blue wire on terminal 87 gets wired to the starter solenoid. I re-used the wire that was in the Silverado harness for this. Terminal 85 is connected to ground and terminal 86 gets wired to the Tacoma ignition switch.

 

For automatic transmissions with a lock up torque converter, the PCM needs to know when the brakes are pressed, so the torque converter clutch (TCC) can be unlocked.

Here is the Tacoma brake switch:




And the wires going to it:



I believe the green/white wire is for activating the brake lights? Someone can correct me if I'm wrong. I also believe the blue/white wire was for turning off cruise control which I won't be hooking up for now. So the plan is to use that wire for the TCC brake switch.

My documentation is not great for this, but I want to say I did the following for wiring. The PCM needs 12 volts on TCC brake (pin 33 in the blue connector) when the brake is not pressed. The green/yellow wire is connected to 12 V and connects to the blue/white wire when the brake pedal is not pressed. When braking the switch cuts the 12 volts to the blue/white wire (and supplies 12 volts to the green/white wire, sending power to brake lights). So I want to say I just wired TCC to the blue/white wire.

 

The PCM outputs a 4000 pulse per mile vehicle speed signal (VSS), from pin 50 in the GM PCM green connector. I wired this the to green/red wire (pin 2, VSS) in the brown connector D behind the speedometer.





This signal can be calibrated by a tuner and controls the speedometer. I can confirm the Tacoma speedometer works with this signal!

I also connected the tachometer (Engine Speed Signal, pin 10 in the green GM PCM connector) signal from the PCM to the black wire in the blue connector behind the speedometer, based on a post in this thread:https://www.tacomaworld.com/threads/aftermarket-tach-install-which-wire-to-tap-into.227116/



This did not work. Here is the pin diagram for the 10 wires in this connector:


It looks like the black wire is pin 3, which is "Seat Belt Buckle Switch" or it might be a ground? I don't think any of the wires in that connector feed a signal to the tach, so I need to do some more research to get the tach to work. Here are the pinout names for the wires in the 4 connectors behind the speedometer:



I'm not sure which one to connect to to feed the tach a signal?

 

Just got done reading... waiting to read some more.

For a member with only 88 posts, these are interesting as hell.

Subbed

 

Ok I think I figured out where I went wrong with the tach signal. The tach signal normally comes from the ECM or igniter in the Tacoma, black wire in the diagram below:



It looks like it is in the same connector as the VSS signal, two pins over on pin 4. I will try connecting to that wire next time I have the speedo off.

 

For the OBD2 port wiring, you will need 12 V constant power to pin 16, ground wired to pins 4 & 5, and pin 2 wired to the serial data from the PCM (pin 58 blue connector). I went ahead and put in an all new OBD2 port but you can likely re-pin the stock Tacoma one if you have one in your truck already. I went with the cheap Panlong bluetooth scanner and it has been useful for monitoring things.



The last bit of wiring is to the check engine light. Pin 46 in the green connector supplies 12 volts when the CEL is set. I connected this to an LED and installed in the dash to the left of the steering wheel (dusty I know).

 

Here is the finished wiring harness before going onto the truck.



The wires coming of the left side of the block are mostly for emission stuff (evap purge, evap vent, gas tank pressure sensor, extra ground)


This branch of wiring will be going into the cab (VSS, tach, OBD2, CEL, TCC brake, Ignition switch,etc). Also shown is the connector (gray and red) that goes to the Throttle Actuator Controller (TAC) module. I went with drive by wire, since the harness was already wired for it and the electronic throttle body was already installed on the intake.


And here are the blue and green connectors that connect to the Silverado PCM.


And the full harness ready to go on the truck.

 

Next step is to get the harness attached. This harness was originally on the engine so all the connectors are in place. I left all AC connectors in the harness and just covered them for now.



Fuse block and PCM will be located on the left side of the engine bay, where the battery and evap charcoal canister used to be.


Here is what I ended up doing, its super ugly but working for now. An L-shaped sheet metal bracket is holding the PCM. The fuse block is just tucked away where the evap charcoal canister used to be. I plan to fix this ugly rat nest in the future, or at least cover it up.

 

The engine I purchased did not come with the original drive by wire (electronic) gas pedal so I purchased a used one off of Ebay for $61. It included the pedal assembly, throttle actuator controller (TAC) module, and wire harness that goes between the pedal and TAC module. The TAC module gets mounted in the engine bay and connects to the main engine wire harness, allowing it to talk to the PCM. My PCM was programmed to be used with drive by wire but it could also be programmed to be run drive by cable, but I would have had to purchase a cable actuated throttle body.



The GM pedal is too long. I used this guy's idea to marry the Toyota pedal to the GM:

https://youtu.be/Q4ojUcAw1lM

Initial test fits of the pedal:


And welded up:


I ended up not liking the position after welding, so I cut a notch halfway down the pedal, bent it and re-welded. This is what I ended up with:

 

I was able to re-use one of the two stock Tacoma pedal bolts. I had to drill a 2nd hole in the GM pedal base and through the firewall. I used a bolt and nut in the engine bay to secure. You can see the two bolts at the bottom of the pedal assembly I used in the image below. The parking brake pulley to the left of the pedal has to be taken off in order to get the GM pedal in and out. It barely fits.

 

The 4l60E automatic transmission needs a shifter in the cab. I was able to re-use the stock Tacoma shifter by coupling the end of the Toyota shift bracket in the trans tunnel to the 4L60E gear selection rod that sticks out the side of the transmission case. The coupling consists of a threaded rod with internally threaded ball joint rod ends on each side. A custom lever was made that bolts to the 4L60E gear selection rod on one side and then attaches to the ball joint on the other. I did not measure lengths or get any good pictures of the components before installing, but I will in the future. This is a temporary solution as I am only able to shift to park, reverse, neutral, and drive. Not the best but this is the budget friendly option, use what you have. I will give an update when I upgrade the shifter in the future.

Not the best pictures:

 

For emissions, I kept the Tacoma charcoal canister in the engine bay but relocated it to the passenger side.



Here is a diagram of the connections I made to the Toyota charcoal canister:



B and D are normally connected between the Toyota VSV and pressure sensor. I got rid of those and B and D are just capped. The air drain E is left open, it is a vent if pressure gets too high in the canister and is normally dumped into the frame rail. The gas tank vapors flow into A. I put the GM gas tank pressure sensor in line between the gas tank vapor hard line and the connection to A on the canister. I used a tee and clamps to make it work. The GM sensor is normally mounted directly to the gas tank. The three white wires coming off the sensor are connected to the PCM and are a 5V reference, pressure sensor signal, and ground.



The GM filtered vent valve solenoid gets connected to F. The PCM controls this solenoid, allowing fresh air to be sucked into the charcoal canister to get mixed with the gas vapors.

The purge valve solenoid is located on top of the intake manifold and this gets connected to C on the charcoal canister. The PCM opens this valve when the engine is running to allow the vapors from the charcoal canister to get dumped into the intake manifold and then burned in the combustion chambers. The engine wire harness still had the purge valve solenoid connector attached so all I had to do was just plug it into the solenoid. The right angle vacuum connector shown below ended up splitting so I need to find a better solution.



I have O2 sensors installed before and after the cats. The last bit of the emissions equation required to clear the readiness monitors (vehicle emission self tests) was the PCM needing to know the fuel tank level. I did not connect the Tacoma fuel level gauge to the PCM but rather just tricked the PCM to thinking the fuel tank is at 50% by grounding PCM wire 54 in the green connector through a 150 ohm resistor. The GM fuel level sensor in the gas tank varies from 40 to 250 ohm, from empty to full. That did the trick and all my readiness monitors cleared, allowing me to pass emissions via an OBD2 check!

 

Here are some pictures of the finished engine bay:

 

And start up!

https://vimeo.com/450877735

 

So how much did the swap cost me? I spent a total of $5,256 but $715 was for tools and equipment I did not have.

Here is the cost break down:
https://docs.google.com/spreadsheet...oI5/pub?gid=1349165347&single=true&output=pdf

I already had a welder before starting the project, a Vulcan OmniPro 220 with CO2 shielding gas. I have about $1,200 in my current welding setup.

I still have the 5VZ-FE V6 engine, transmission, front differential, and a few other Tacoma parts that I could likely sell to get a little money back, maybe $500. So likely the bare minimum budget swap cost would be around $4,000 (assuming your setup with all the tools already and you sell some Tacoma parts).

 

I'm responding mainly to move it up my subscriptions while I reference it... but my biggest question to the community would be how much difference would this build be for a 2.4l 5lugger frame and a manual tranny?!

 

2.4 means your already a 5lug and won't have to deal with the front diff/axles. You'll also have better options for lowering the truck if you're looking to do that. Frome differences would be minimal and the motor mounts are different but you'll have to navigate that regardless. Otherwise I think it should be very parallel to what's described here. I'm following a similar path as this with an LM7 and TKX trans in a 4x4 frame.

 

Check out Tom's Turbo Garage build: https://youtu.be/ZRewZb8naGg?feature=shared