The Most Regular Cab (a restoration)

Last year, I hit up a guy on Marketplace who was selling a 1st gen Tundra, or at least that's what I think I remember. In typical Marketplace fashion, there was no response...until 6 months later. He said he had been in Mexico but was now back in town and re-listing his items and noticed my question about the Tundra. Funny thing, though, is he told me the Tundra had sold but was now wondering if I was interested in his nearly broke-down, blown-head-gasket 95.5 regular cab?

A cheap Tacoma? It was worth taking a look.



Long story short, this stray followed me home. It was mostly rust free, kinda straight, dirty, neglected, and nearly blown up but it was pretty cheap. I had a new project and figured if I got it running reliably again, it would be something that would replace my old 4wheeler on the farm.

I got to work cleaning




What I didn't notice, because I didn't know this beforehand about the 3RZ platform, is that this blown motor wasn't the original. What I discovered was someone had swapped out a dual coil 3RZ for the stock distributor motor at some point in the past. I always thought all 3RZ's were either dual coil or coil pack motors, so when I saw dual coils on a 95.5, I didn't even think to look for engine swap shenanigans. Turns out the cab wire harness was hacked up and that's why indicator lights and my scan gauge weren't working. Bummer. Knowing what I know now, I likely should have passed on this one. But I was stuck now.

ECM butt splicing? Oh $#@!


Swallowing this pill and accepting my fate, I got to work cleaning and degreasing, then the work began of finding a motor. My other mistake in all of this was assuming 3RZ's could be found for $1200-$1800 like the pre-Covid days. I found out the hard way this was not so. Used JDM motors locally and nationally were in the $3k-$4k range now. WTF? 4 Grand for a used 4banger?

I kept looking. I went back and fourth about what to do. I researched 5VZ swaps, LS swaps, 1UZ swaps and kept scouring the classifieds for 3RZ motors. I finally made the decision to have Sunwest build me a longblock. I placed the order on April 2nd and they told me, even though their website said 3 weeks, that it would be more like 5 weeks. Ok, I guess.

In that time, I missed out on a really good local deal for a 3RZ with 180k on it. A couple other used 3RZ's popped up including one from a 2000 4Runner that had 250k on the bottom-end but came with a fresh head, serviced, gone through with lots of extra parts included. But Sunwest was building me up something good (or so I thought).

Mid-May came and went and I hadn't heard anything from Sunwest, though. I gave them a call and they told me they were still waiting on a core to build and there were some issues sourcing parts. During this time there was lots of tariff talk and the threat of import parts going up so I wasn't happy about the delay but was already this far in with them, so had no choice but to wait. It still got to me that they hadn't let me know about any delays without me having to call and pester them and I felt that was pretty unprofessional. When I asked them about a timeframe for completion, the lady couldn't give me an estimate and said she would let me know in a couple weeks. That seemed a little off, too.

In that time, the gone-through used 2000 4Runner's 3RZ for sale on Marketplace went from $3500 to $3000 to $2500 and landed at $1800. I figured there were at least $1000 worth of additional parts included so I just had to run over the mountain to take a look.

I made the trip out to Happy Valley, OR.




Good communication from the seller, pictures of a tidy shop, and the receipt folder pic all had me optimistic, but when I rolled up to the address and saw 2 very nice and clean 3rd gen 4Runners, I knew I was in the right spot. I spent 3 hours there chatting Toyotas with Jake and his dad Jason, looking at their projects and going through this motor. Turns out, the guys had done a 5VZ-FE swap and a 4x4 swap on a 2000 4x2, 3RZ powered 4Runner. We checked out the 4Runner and the swap looked factory. It was sweet. All the parts he was selling was off of this 4Runner, too, which was a beauty, 1-owner (before him) rig.

I was locked in. We made a deal and then figured out how to build out a pallet for transport to get everything safely over the mountain and home. Some new friends made, a gallon of their apple cider included in the deal and I've got my hands full with a bigger project then I think I bargained for.

 

With the new motor home, I set out to getting the remaining parts on order and prepping for install. I also called Sunwest, canceled my order and asked for my deposit back, saying it had been two months with no definite completion date on the near horizon with zero communication indicating their timeframe. With the cancelation, they quickly scrambled and told me the motor would be ready Friday of this week. I told them I was canceling my order and I didn't want the motor. They said, fine, but told me the deposit was non-refundable. You can PM me for the remaining details but I now feel pretty strongly that Sunwest can eat a kingsize bag of dicks. Zero out of 5 stars.

Anyway...the old motor coming out (with a painted valve cover. I thought that was going on the new Sunwest long block. Nope).


Yuck, so much gunk.




After a degrease time to hit everything up with Rustoleum Rust Converter and do a shitty job repainting the battery box area.





And hit the suspension and frame, too.



No torn down pics, but am happy with the results (with some new ARC splash guards)

 

I had a couple of flywheels now. Both looked to be in good shape without needing a resurfacing. The one I used had less than 12k miles on it. New hardware of course.




New clutch, pressure plate, TOB and slave, too.





Lotta other new parts too.



And some paint work and resto on the accessories including the LCE header. I also took the time to rebuild the starter but didn't get pics of that.





Time to get organized for install



Now...through the magic of the internet, it's in!







Along with some fancy kit for good measure



And now this poor little neglected truck has had all 3 types of 3RZ's installed (distributor-8 port, dual coil-8 port, coil pack-4 port. Was there a dual coil, 4 port?) Anyway, with the engine bay back together, the easy part was done. Now to figure out this fuct up wiring situation I squarely got myself in. Stay tuned!

 

The motor package came with everything to get the 3RZ running, including the ECM and wiring harnesses. In fact, he labeled it as a full 3RZ swap package. Would have been pretty cool to put it in an 80's mini-truck.

That said, after pulling the motor wiring harness through the cab, it became immediately clear the cab harness connector from the Tacoma was not the same as what went in to the new ECU. That's ok, though, because that's the connector that was cut and butt-spliced by someone in the past on this Tacoma.

Time to get busy figuring out the wiring order of the far-right connector (E8). Of course, I turned to Tacoma World and Dm93 (I won't tag him here as he seems to be tagged every 20 minutes on TW, so I'll give him a break).




The nice thing was I had the cab wiring harness from the package deal to compare to the diagrams. There were 10 wires on the old connector and 12 on the new ECM to figure out.



You guys here on Tacoma World came through. Sandman614 got me wiring diagrams and others answered my questions about function abbreviations. Turns out there were lots and lots of changes from 95.5 to 2000 including SRS stuff, OBD1 to OBD2 stuff, other safety system changes, emissions systems, etc. etc. I spent more time than I'd like to admit going back and fourth staring at diagrams then comparing connectors.



While looking at the connector attached to the complicated 4Runner's cab harness with lots and lots of systems I didn't even have on the Tacoma, I made the decision not to use the included 4Runner cab harness. With that decided, I then decided to not hack up the cab harness, either, thinking I could sell it complete. So I ended up ordering a used E8 connector on Ebay and de-pinning it. Turns out this connector is used in lots of Toyota applications including the 2JZ Supra and IS300. This one came off a Supra, so hopefully it will be extra fast!

There were only 10 or 12 wires needed for the Tacoma so here I'm removing wires from the Supra connector.


I also found the connector and pins on Corsa Technic. It's:
( 22-Way Housing (MLC040IIIHD-22S) - Multilock 040 III High Density Series ). My thought was that when I got everything up and running, I could go back and re-pin it with the new connector.

The package deal also came with a deluxe gauge cluster from a 4Runner. I always liked the 4Runner font and look of the cluster so I was excited to swap that out and have a factory tach, too.

Here's the original base Tacoma cluster


And the deluxe 4Runner cluster


Unfortunately, what I found is the 95.5-97 speedo input is mechanical and after that, they went to an electronic signal off of the ABS system. This little regular cab was the base model of base models so it didn't have ABS to try to Frankenstein a signal off of. So I was left with either A): doing a conversion and chopping up the 2 clusters I had to try to make one. B): finding the right cluster. A quick search on Ebay turned up a 1997 Tacoma 3RZ (important for the tach; 4cyliner vs. 6), 5spd, 4x4 cluster for a reasonable price. At this point in all of this, I already had my heart set on a factory tach and this would be an easy plug& play swap so I made the guy an offer on Ebay.

He accepted!


With the new gauge cluster having arrived (I was swimming in 90's era clusters!), the install was super-easy. And now that E8 was sorted, every connector under the dash had a home and was plugged in. The time had come for a 1st start and I scrambled to fire it up. Engine oil: check. Coolant: check. PSteering fluid: check. Clutch: bled. New battery: installed. All connectors in the engine bay connected: check.

Key on: check.

Dash lights: Not all on. Hmm.

Engine: Crank. Crank. Crank. No start.

Dang.

The saga continues....

 

If you're following along and want any of the parts I didn't use, they're 4sale here:

3RZ Shop Clean-up Sale | Tacoma World

2TR/3RZ-R150f bellhousing, R150 internals | Tacoma World

 

First things first, I plugged in my scan tool to try and get some error codes to work off of.

Link error, just like before. That's a bummer.

I set out to figure out why the OBD port wasn't working.

Looking at a more modern OBDII pinout, the diagram had 8 wires. I still had the dash apart so it was easy to see I only had 4 wires going to this connector.



I needed to find a simpler configuration. I lucked out and found this image from an older Camry.



I had 12v at Pin 16, continuity to ground at Pin 4 and Pin 5. I knew K-Line (Pin 7) was plugged in to the ECM because that was part of the E8 connector decoding I had done, but going off the simple diagram above, I decided to de-pin 7 and re-insert it in to Pin 2 like the Camry's indicated. I plugged my scanner back in and it worked immediately!!

It also gave me a couple of codes (an MAF code, 2 IAC codes and, after a search, I found out that if those sensors were erroring, the ECM wouldn't provide spark). Pulling the connector from the coil pack, adding an old coil pack, inserting an old spark plug and grounding it on the throttle body so I could see it spark or not through the windshield while cranking confirmed there was no spark happening.

Well, at least the scanner worked now!

I set to work re-checking over everything in the engine bay (and plugged the new coil pack back in to the motor), paying extra attention to the MAF and IAC sensors and whether or not they were truly connected. They appeared to be with the audible "snick" you want to hear when connecting. I re-checked everything under the driver dash (not much there, I thought, but pulled out and checked all the fuses and replaced the EFI fuse for good measure), then set to work under the passenger dash.

You know those Eureka moments where you figure out the issue but you also feel like an idiot? Eureka Dunce? Lite bulb/forehead smack? Yeah...that was happening now.

The IK2 connector under the dash (the big one!) was connected to the only other connector that fit from the new coil pack/4Runner motor. When I was in the motor-install phase and just jamming along, I plugged everything in together that quickly fit. It all had a home except for that one E8 connector at the ECM. The IK2 connector from the Tacoma's cab went right into the 4Runner's without a 2nd thought, I heard the snick and moved on to the next thing. At the time, I didn't even think there'd be issues with that. They fit together and that was that.

Here are the connectors I'm talking about:



This is the Tacoma cab-side



And the 4Runner's engine side



On closer inspection, nothing matched. Not even the wire colors. Son of a.... that had to be it!

Well. At least I knew what to do next. I hopped on the desktop and searched and read every "no spark 3RZ" and "3RZ conversion" I could find. There was lots of info out there, including lots of 3RZ swap info but none that I could find from a coil pack motor (IH8Mud, Pirate and CustomTacos all had basic 3RZ conversions but from dual coil or distributor motors and they all seemed to go to much simpler applications ie 22RE swaps).

But Tacoma World had me again and I found an excellent thread started by and followed up by Zack3rz here:

(Solved) 3rz starts and dies, no CEL | Page 8 | Tacoma World

Even on non-shop days, I love reading "Solved" threads and appreciate those members who go back and update the thread with their solution. This one, as it turns out, along with the members that posted there, solved my issue and I couldn't have figured it out without the info there including the "solved" update.

Dm93 had posted there and I bumped the thread. He responded and PM'd me the complete 1995.5 wiring diagrams and the 2000 4Runners. I already had the ECM pinouts for those trucks but was super thankful to have the complete diagrams. From those, I figured out that the connector I had in question was called the IK2 connector. I had lots of important stuff on it including power to the ECM, grounds, temperature gauge, tach signal, dash lights but most importantly, power to the MAF and IAC! That had to be it!!

It was a late night and early morning of studying the pages and pages of diagrams Dm93 sent me and trying to make sense of it on paper. I haven't studied this hard in a while.



I had the 95.5 figured out, but I couldn't for the life of me find the IK2 connector on the 2000 4Runner's diagrams. I searched and searched, gave up frustrated and asked TW in a thread and PM'd Dm93. He couldn't find it either.

It took more time than I'd like to admit to figure out that the IK2 connector functions had been renamed the II3 connector on the 4Runner diagrams. It contained all the functions of IK2 including several others like ABS, SRS, but all of the Tacoma stuff too (including the ECM, MAF and IAC power). So that was it! I could now study each diagram and every time I saw II3 in a little box, I traced to where it went and what it did. I could then rule out wire/pins that had functions I didn't have on the Tacoma (like ABS, passenger SRS, etc) and would depin those wires, heat shrink them and terminate them.

It's funny to type this out and look back at the pictures. The dialogue makes it seem like I had a logical, step by step plan but in reality, I felt like a blind squirrel looking for a nut with tons of time between each little relavent moment. Thankfully, this little base Tacoma was about as simple as a "modern" car could be. It was kind of astonishing to see how much more complex the 4Runner was just a few production years later.

Now that I had everything sussed out on paper, voltmeter confirming my findings, it was time to de-pin and re-pin the connectors.


I chose to keep the 4Runner II3 side intact and de-pin and reorient the IK2 of the Tacoma's cab to match. I'd made a map of what goes where, but it was still a little confusing. It took me a couple tries to get it right. But when I did, all dash lights turned on with the ignition (SRS, e-brake, check engine, seat belt, gas gauge, etc.) and there was only one thing left to do: blast off.

Crank, Crank, Crank. Nothing!! ARRRGHHHHH!

I went back and triple checked everything. Long story shorter, turns out, just like Zach's truck, pin 5 on the IK2 harness was missing/not in place and just like Zach's truck someone cut the G-Y Circuit Opening Relay wire. On mine, someone tucked it back so far behind the dash wires, I didn't even notice the cut wire or the cut barrel connector. It's times like this I hate used vehicles. I would have some strong words for the culprit who cut the wires or at least questions for what the hell they were doing. How did the old truck even run with the COR cut? And times like this I say I'm never buying a used vehicle again (lol. All the vehicles I own are previously used vehicles. LOL).

After one last depinning of the donor engine's harness and connecting the cut COR wire to the donor motor's correct pin, the truck sputtered to life for the first time since April.

 

I have friends that get bored. I have colleagues that complain about depression while they're twiddling their thumbs at home without a purpose outside of work. I have younger relatives that spend countless hours playing video games. I have older relatives that are about to retire and are worried about what they'll do with all their new free time. To all of them, I say get a shitty old car that doesn't run and make it run again.



One more saga so far though. With the truck running pretty well, I buttoned everything up, re-installed the hood, a new grill, those newly painted little filler plates under the grill and put the bench seat in, unbolted to the cab, and took a lap around the farm. Happily crusing along, I glanced at the gauges that were working including tach and speedo. I glanced over to the temp gauge and FML! it was pinned beyond hot. I snapped the ignition off and rolled to a stop. Crap!! I plugged the scanner in and looked at the live data. Coolant temp was 185 degrees. Oh thank God.

In addition to lots of other little things (got the 4x4 dash light to work; no small feat on a 4x2 wiring harness!), this temp gauge is an issue to sort through. With the 4Runner motor temp sensor, the temperature is pinned beyond hot. When I plug in the old Tacoma motor sensor, the temp is cold cold, even when dipped in to my morning coffee and left to sit. If anyone has any answers there, I'm all ears.

I have some FJ Cruiser Trail Teams wheels I'll have wrapped in A/T tires, a pipe rack and tool boxes to add, in addition to figuring out how to recover the bench seat but that's it for this little rig for the time being. For now, thanks for following along!!

 

Holy shit what a saga!
You performed a miracle on that truck!
Congrats on salvaging it. I’m not sure what percentage of the population could have had the patience and determination to pull that off but it’s probably less that 0.1%.

 

I really appreciate it. It was the perfect combination of being too dumb to know any better and just smart enough to get out of the trap I set for myself!

Thanks for reading and following along. I had to get it down and out of my brain so I can refer to it when I have the "good" idea of buying another non-running vehicle thinking I can get it going again for cheap.