1998 Tacoma 5.3L Vortec (LS) Engine Swap Thread

Well played!

 

I re-used the stock Silverado fuel injectors:



I popped them off the fuel rail and cleaned them, making sure each was working. I stole this guy's injector cleaning method:
https://youtu.be/rUUgR94drxg

I used a switched 9V battery to quickly turn the injector off and on as I was pressurizing it with carb cleaner. They heat up quick so avoid keeping them on for a long time or you can damage. I don't have any pictures of the injectors being cleaned, so you can imagine the injector installed in the tire valve stem below and the carb cleaner attached at the right end of the red straw.

 

Now jumping to engine cooling, working to keep the stock Tacoma radiator. I first re-positioned the Chevy water pump outlet by heating it up with a torch and then rotating it clockwise as far as possible.



Here was an initial mock up re-using a piece of Tacoma hose to connect the pump outlet to the Tacoma radiator input.



The problem with the above is that there is no room for a cold air intake tube to go over or under it. A short filter right on the throttle body may have fit but I've read a filter attached there is not the best for the engine.

For coupling the water pump input to the radiator output, I bent a piece of 1.5" aluminum tubing on my bender.



And I learned that benders designed for steel tubing do not provide a smooth bend on the inside radius of aluminum tubing, see the three dimples below. I used cut up sections of stock Silverado hose to connect everything. Initially I connected the heater lines together using this bypass hose, Dayco 87629 (

$14 Dayco 87629 Small Id Hose

https://www.amazon.com/gp/product/B000C0YQGM/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1)

 

Here is how I oriented the upper radiator hose, this gives enough room for the cold air intake to lay over.


I ran the cylinder head crossover tube/steam vent to the upper radiator hose using an ICT billet radiator hose barb coupler:

$27 ICT Billet Radiator Hose Barb Coupler with 1/8" NPT Port 1-1/4" Steam Tube Adapter for LS Swap Steam/Coolant Crossover Splice Made in the USA Billet Aluminum AN627-20X125

https://www.amazon.com/gp/product/B07PW3YCZM/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

 

I re-used the Tacoma starter power wire. Due to the cables short length, I re-located the battery to the passenger side so it could easily reach the 5.3 starter which is also on the passenger side. I first fabricated a battery tray out of angle iron.



The tray bolts to the fender. I re-used the stock battery hold down clamp.

 

For the cold air intake, I went with a cheap 4":

$58 SUPERFASTRACING 4" Cold Air Intake System + Heat Shield Replacement for 1999-2006 GMC/Chevy V8 4.8L/5.3L/6.0L Silverado 1500/2500/3500 (Black)

https://www.amazon.com/gp/product/B07GZDPNJQ/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

It came with a heat shield which I modified to fit next to the battery. One of the tab mounts lined up with an existing threaded hole in the fender here, so I used that to secure it in place.


The 4" aluminum intake tube had to be shortened a bit to get the filter to sit in the shield.



A Suburban MAF sensor was sourced from the junkyard and is coupled to the intake via a Spectre Performance coupler:

$23 Spectre Performance 9771 Black 4" Intake Coupler

https://www.amazon.com/gp/product/B001OMK53K/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1





Heater hoses were also hooked up to the stock Tacoma heater inlet/outlets behind the engine.

 

For the radiator fan, I went with a 16" 2036 cfm SPAL electric pusher fan (part #30102047): https://www.summitracing.com/parts/spu-ix-30102047

I mounted it in front of the radiator, where the AC condenser normally mounts. So no AC for now but I have plans to add it back in the future.


This fan is LOUD but it works well. I will cover the relay wiring in a later post.

 

Your not long from driving this thing!

 

@jimmy johnny , very impressed with your improvised work arounds. you've obviously been wrenching and modifying engines for some time, or you have an overly active imagination. Keep us posted on this venture, I'm waiting to see it up and running.

 

Ok next I will cover how I went about wiring everything:


The wiring harness looks crazy but it's really not that bad. I did all the wiring myself but you can pay someone to do this for you.

These videos helped me out a lot with the do-it-yourself approach:

https://www.youtube.com/watch?v=92MV5gBonls

https://www.youtube.com/watch?v=RHIVd_SkB9Y

https://www.youtube.com/watch?v=n5LFWjJjHZ8

Tons of information here: http://lt1swap.com/2000harness.htm

You will first want to remove and label all the wires from the stock Chevy fuse block and fuse block connectors. The videos above show how to do this. You can also remove unused wires to make the wire harness not so bulky, the videos above also show how to do this. I decided to just keep them in the harness to save time, they won't hurt anything staying.

The Chevy fuse block is big and bulky. I went with the same fuse block called out at lt1swap: http://lt1swap.com/fuseblock_obd2port.html

Amazon link to fuse block:

$10 Dorman 85668 Fuse Block Holds 4 Blade Fuses Universal Fit

https://www.amazon.com/gp/product/B000CO7I04/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

Instead of one, I used two fuse blocks side-by-side to get me a total of 8 available fuses. I also used four relays:

- Main relay
- Fuel pump relay
- Fan relay
- Starter relay

Here are the relays I used (4 Pack - EPAuto 30/40 AMP Relay Harness Spdt 12V Bosch Style), they came with holders:

$12 EPAuto 30/40 AMP Relay Harness Spdt 12V Bosch Style - 4 Pack

https://www.amazon.com/gp/product/B072QXDZRD/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

Here are the two fuse blocks and relays connected together:


The PCM and fuse block will stay on the driver side of the engine bay. So I will not be extending wires to place the PCM in the cab. This is the simplest approach. This was another reason for re-locating the battery to the passenger side.

I will next show how I wired the fuse block and relays.

 

Let's start with the main relay. I put together some simple diagrams to show how power gets routed through the relay socket and to the fuse block. It's similar to the fancy diagrams here: https://www.rx7club.com/v-8-powered-rx-7s-299/l31-5-7-vortec-swap-help-1121434/

These diagrams are a view from the bottom of the fuse block and relays when connected together.




12 V from the truck battery gets wired to this relay socket:



The main relay gets powered on only when the key is in the ignition and the engine running. When the key is out of the ignition, no power gets to these fuses. Three fuses in block 1 are wired in parallel to share the same 12 V from this relay:



The relay gets switched on via a 12V signal from the key ignition switch. Terminal 85 of the relay gets wired to ground, which is part of the key 12 V circuit:



Power is sent to the following components through these 3 fuses:
- 8 injectors
- 8 coil packs
- PCM
- MAF sensor
- Evap purge/vent solenoids
- O2 sensors
- Transmission
- TAC module (drive by wire gas pedal controller)
- Check Engine Light (CEL)


These are all pink wires that are already in the harness. The CEL wire is a new wire that is added. All the wires get divided up among the three fuses, it doesn't matter where they go. I went with 15 amp fuses for each circuit.

 

A portion of the PCM and OBD2 port need constant 12 V power (remains powered with no key in the ignition). The two wires in the harness that go to the PCM are orange. The OBD2 wire is new and should be added to run to the OBD2 port in the cab. The fuse all the way to the left in the diagram will be used to protect these circuits. 12 V gets tapped from the 12 V battery side of the main relay.

 

Now onto the fuel pump relay:


I used a 4th wire from the fused 12 V constant circuit to power the fuel pump relay:


The fuel pump power wire (green) gets connected to terminal 30 and is run to the pump in the fuel tank:



The fuel pump relay is switched off and on via PCM wire 9 in the green connector, dark green and white wire. This wire gets connected to terminal 86 on the fuel pump relay:



And terminal 85 is attached to ground, I connected it the the main relay ground (not shown below):

 

This shit is way over my pay grade, and knowledge base. You guys, that can read and rewire shit have my utmost admiration.

 

When you look at all the wires in the harness, it can seem overwhelming. What helped me was to watch the tutorial videos multiple times before even starting on the work. I then sketched the wiring out on paper to help guide me through the process. Instead of showing you a full wiring diagram, I'm breaking the wiring down into smaller steps here. Hopefully this can help someone else out in the process. Just take it one step at a time.

I know I'm leaving out small details here and there. I'm hoping most will watch the videos first and then use this thread as supplemental. I'm documenting my approach which is similar but slightly different.

 

wait what happened why did you stop?? I want to see it run!

 

Haha, sorry, life happened. Spoiler alert, I've been driving the truck for almost a year now. I hope to get this thread rolling again soon, stay tuned!

 

Almost a year?

 

I'm assuming that all of OPs post were written retroactively and not throughout the course of the process.


Nice work and details, OP