550hp 2JZ 1978 Hilux Build

Your big circle actually BARELY encompasses the little ground wire on the right that is pulled out of the harness and is causing the issues so you're technically correct by a handful of pixels hahahaha

 

So technically, he still earns the beer....

 

Just messing with you, and even my CDO is good with it for a temporary. (CDO is like OCD, but in alphabetical order the way things should be. )

 

Some big strides today! I tore up the harness more and cut out a bunch of useless stuff, mostly going to the transmission but also some other plugs I don't need.



It further turns out that the ground loop that went to the transmission plug originated from the body harness, most of which I didn't have connected. So the TPS and ECT grounds came from the body unlike most of the engine sensors that grounded directly to the engine or through the ECU. With that figured out I buttoned it back up, using abrasive resistant electrical tape.





Annnnnd the TPS now has no positive continuity. Fast forward a bunch and some confusion, and turns out the ECU "B" plug has a 5V reference wire that powers some of the sensors. This wire was NEVER hooked up, so I'm utterly confused as to how those sensors had 5V before. It seems like stuff was shorting and jumping around all sorts of weird. Between wiring the reference 5V to the correct bundle and taking the grounds that went to the body plugs and connecting them to the block, EVERYTHING ended up fixed! Like more stuff ended up fixed than I was trying to fix! The IAT sensor now works, the ECT and TPS works, the motor for the throttle body made a noise, all kinds of stuff now works on the engine!

All the engine codes I had disappeared with the exception of one: the accelerator pedal position sensor (APPS). The IS300 has a semi mechanical but otherwise drive by wire system, so effectively with the APPS missing it was in mechanical limp mode where the mechanical actuator doesn't do anything for the first 50% of travel and then engages, limiting power and fucking with the idle. I'd heard about mechanical conversions so went ahead and took the throttle body apart to see what I could do. Making it fully mechanical only messes with the idle, but there's a physical idle set screw anyways so not a big deal.







Long story short, all that was needed to fix it was take that little lever above and reposition it about 30deg down and that made it all mechanical! I grabbed some steel and welded another arm onto it and I now have full throttle, zero throttle lag, and eliminated the need for the throttle body motor as well as an electromagnet!

The final thing which I figured I had solved was the cooling. To get down to business: the water pump seems to be spinning backwards? It's really weird. We put the radiator hoses into a bucket and the suction and pressure are definitely backwards. The thermostat side is sucking water, which it should be trying to flow hot water over the thermostat not pull in cold water. The pump and pulley are what came on the engine and appear to match the stock routing and setup so shouldn't be spinning backwards. Even with the thermostat removed the truck would overheat, so the only solution I can come up with is the water pump is totally fucked and is somehow barely flowing water backwards but not enough to actually keep the engine cool. If not that I have no idea, but tomorrow morning I'll pull the pump and take it apart and see what the deal is.



This thing really needs the front brakes, and doors, and bolt the seats in, and seat belts, because it is rowdy now that full throttle has been unlocked

EDIT: also the sensor I was confused by was a knock sensor, and the oil pressure switch is off of the oil filter bracket, so that mystery plug off the head I think is literally just a plug.

 

Very impressed with your trouble shooting

 

ITS ALIVE!!! So I'm a moron and the cooling system is not reversed. It turns out the thermostat is in the intake side of the engine which sounds like is somewhat uncommon? Essentially the engine recirculates coolant internally and once it gets hot the thermostat cracks and flushes cold water in which cools the engine and thermostat thus closing it, so the engine tends to run hotter since there is no bypass around the thermostat so it needs to get to full temperature before there's any water flow.

This shouldn't really affect anything since it's a closed system, but since my intake hose off the radiator is on the high side that means any air in the radiator will stop coolant being sucked to the engine--again shouldn't matter until you lose any coolant OR have an air bubble. I jacked up the drivers side so the intake hose off the radiator was on the lower side and then let it warm up and fed it the hose and that seemed to be the key! Bleeding it correctly was the issue the whole time! I took it for a drive and got gas and the hottest it got was 200 (and I don't think the radiator fan is turning on).



I had two instances where the engine died, but they were both after throttle pulls and then punching the clutch so I think it's just the rpm dropping and not recovering before it dies. The one weird thing is I seem to have to turn the ignition off to get it to restart, since just cranking it after it dies didn't work. Kind of odd, need to troubleshoot that more. But it runs and drives and doesn't overheat! Next up is get the front brakes replumbed and install body panels I think

 

When you gonna put the twin turbskies on there?

 

I'm hoping this fall. Get it dialed in now which there's still a lot of things to wrap up, then order parts and once all of it shows up tear the whole truck down so I can build the engine and paint everything. Maybe do suspension work before then too, it'd be nice to get all the fabrication done before I paint the frame.

 

Almost 4 months to the day, and the biggest achievement of them all has happened, the first real drive! Got the front brakes plumber, through the panels back on, and went for a 30 mile drive!





View from inside, right now I'm using my phone sitting in the ash tray as a digital dash connected to the OBD2 port.





















The trip was amazingly successful! This thing is already a blast, and will just get better!

The brakes are absolutely insane, now to be fair the truck weighs about 2300lbs (I weighed it over the weekend at 2195 with a tank of gas and no panels) and the tires are tiny and probably the cheapest 26" tires in the world--- but that electronic booster is absolutely next level and it's stupid easy to lock everything up. Maybe to the point of being dangerous if a stranger got in and drove.

I'm not sure how to wire the ECU to tell the fan to turn on, so I just plugged the ignition block into the fuse relay trigger so the fan is on when the ignition is on, and the hottest the engine got was 185 and I think it has a 180deg thermostat. Now that's not saying much, but I was worried the radiator wouldn't get any airflow and I'd still like to put some scoops under the body to grab air but it seemed like it stayed totally cool the whole time. I'm curious how hot it'll get without the fan on at speed, but the cooling system seems to be working!

The transmission is great! Though I dropped into 3rd and 4th and 5th unintentionally way more than I'd like to admit. Luckily the 2jz has a nearly 7000rpm stock redline plus I wasn't going very fast, but I'm used to the FJ40 which has only 4 gears and a lot of throw between them. Finding 6th is especially hard, though it might just be my worry of it hitting reverse and not pushing to the right hard enough. A stock transmission has a reverse lock out which my shifter got rid of, though it'll grind and not drop into reverse over a few mph obviously but it's still a fear I have. The FJ40 you have to very intentionally go into reverse, this is like a 1/4" difference between 6th and reverse. With that said the transmission is already a blast, I've never driven anything with 6 speeds and with the 4.10 rear ratio you go through all of them pretty fast if you want! 3000rpm in 6th is just shy of 70mph, so it's definitely geared a bit short. The gearing is about 30% lower than a stock 350Z rear end I think.

The steering and handling are kind of what you'd expect out of an old vehicle, but honestly comparing to the FJ again it feels great. The steering wheel seems to have a good bit of slop but it doesn't wander at all, and it brakes straight. The FJ is a bit of a work out to keep pointed straight and this thing just cruised.

The one issue I did have is right at 5000rpm the ignition turns off. This is the same issue I mentioned from the other day but now I have it figured it out. I have to fully turn the ignition off and on and then it's fine, but it's right around 5k every time and it dies. I'm thinking since I have one 30A relay powering my ignition bus bar that then powers a bunch of other 30A rated things that maybe a relay is just acting like a breaker and turning off power to the bus bar? But I think the fuel pump stays on which should turn off if the ignition goes off, so maybe it's something else. But it's definitely the ecu or igniter turning off from what I'm guessing is too much power draw for what I'm supplying at high rpm with a lot of spark. That's my theory at least. Just another one of those wiring things that needs to be done properly, hopefully. But on that note the ECU turns off and isn't drawing power after I turn it off! I don't know why it stopped doing that but it's fixed

Oh and one final thing, it is INSANELY loud. It needs a muffler asap, we had to wear ear muffs for the whole drive since it's so fucking loud. People are like I want a loud exhaust, you haven't heard loud until you have a 12" long pipe off the header flange pointed at the floorboard. God it's fucking horrible, but it does snap crackle and pop during shifts which is entertaining

Lots more to come, but today was a huge day where the truck transformed into an actually useable little toy that will now get upgraded and improved on instead of a single huge undertaking to make something functional. I can take it to lunch and keep improving it and not feel like I bit off more than I can chew with each little modification!

Thanks for reading and enjoying this milestone and 4 months of hard work!

 

Awesome stuff, congrats and a big internet high5. The flylux looks like a kids electric toy next to the Tundra.

 

Love the knobs and gauges on the dash. Hope you get to keep them.

Great thread - - great job.

 

Man that's so little next to the Tundra!! What a blast it must be to drive. You cleaned up the wire harness in the engine bay like a champ!!

 

Love it is too weak!

 

Got my license plate today and I'm oddly excited by it



I still haven't figured out the 5000rpm issue. It gets even weirder, I've narrowed it down to the injectors turn off at 5000rpm and the ignition needs to be switched off and on for them to work again. It has spark, timing, everything on the OBD2 appears totally normal but at exactly 5000rpm the injectors just turn off like a breaker gets flipped and needs to be reset. They have power, and can be manually engaged, but don't seem to be getting a signal from the ECU. The only check engine light is for the accelerator pedal position sensor, but it always has that code and doesn't blow anything after it dies. Its not load related either, neutral, 1st, 4th, doesn't matter. It'll die and I can just flick the key off and on and let the clutch out and it'll fire back up. And I can't find a single relatable story anywhere on the internet, I even called the guy that flashed the ecu and he's never heard of that happening. I took the ECU apart today and all the capacitors and stuff looked visually fine. I'm at a complete loss. I ordered an oscilloscope that's showing up Saturday, and hopefully can find a sensor acting weird. And of course I don't know anyone with a 2jz to swap ecus with. It runs like an absolute champ and thinks it's running fine afterwards but 5000rpm comes around and only the injectors and nothing else all shit themselves. I even moved the wiring around to make sure the injectors and ECU were isolated from each other.

 

Today felt like another big accomplishment! After fucking around with the engine more and joining an IS300 forum of which people just told me to replace the acceleration pedal position sensor which I had a CEL for, I found in the description of a YouTube video for the pedal sensor that it could cause limp mode issues. Fixing the CEL seemed like the obvious path forward since nothing else was blatantly wrong, even though there was no indication of my issue from that. The pedal position sensor it turns out has really weird wiring, and it was never connected to the ECU which seemed weird considering I was getting a CEL for it. The wiring for the sensor runs into the body harness plugs and then there's inputs back into the ECU from the body that carries those same wires. Just like the TPS and CTS, they talk to the ECU but don't directly go to it for who knows why. After tearing the harness down AGAIN just to find that all I had to do was connect two pigtails on two plugs, the pedal position sensor finally could talk to the ECU! Annnnnd that fixed it!

Again, who knows why, but the sensor being disconnected from the ECU was stopping it revving over 5000rpm. Now, an explanation of the drive by wire system: you push the pedal which pulls a cable connected to the throttle body butterfly valve. In stock form there is no motion until about 50% throttle and then as a mechanical backup the butterfly can be physically actuated. What happens is you give it throttle, the accelerator pedal position sensor reads that motion in the cable and tells the ECU which then tells a motor to move, which is then monitored by the TPS and tells the ECU it moved. So you effectively give the ECU an electronic input with one sensor, a motor moves which actuates the butterfly, and the TPS gives the ECU the output of what happened. The reason all of this is important is I had to remove the little tab I had welded on to "manually convert" the throttle body since I had fear that the motor would try to override the physical motions I'd give the throttle. On the plus side though, after some testing it seems that the actuator motor is completely dumb (thus why the TPS exists downstream of it) since unplugging the motor doesn't throw a CEL. So after reconverting the actuator to a manual setup and unplugging the motor, and having the pedal position sensor doing something (which doesn't really matter? Because the TPS is what tells the ECU that the butterfly opened...) now I have full throttle and it's all manually controlled!

That was pretty drawn out to say that today I went for the first drive where everything seemed to function perfectly! And the Hilux is an absolute blast! Bouncing off the limiter and shifting through the gears is amazing. The engine seems to want to rev and peak torque and horsepower are both at 6000+rpm, so being able to go over 5000rpm is actually quite noticeable. I even took it up to 100mph, and besides a driveshaft wobble (from installing the wrong axle shims) it felt solid. I'm probably gonna weld the rear sooner rather than later since just rolling into first or second feels like one tire is just burning out. I also think I'm going to run the exhaust to behind the cab and that should fix 90% of the noise issues. I had been considering just turboing it now on low boost to help with the exhaust but I want to run it N/A for a bit to make sure it's happy.

Here's a little walk-around video:

https://youtube.com/shorts/feqhsvYm2UI?feature=share

 

Smooth like a sewing machine! Those tires look like they're rated for about 48mph...

 

uhhh... I was gonna throw a turbo on it; low boost of course; ya know, just to help w/exhaust issues!!!!

 

Hahahaha that made me laugh, it's so sad and so true

Okay but hear me out, it's getting a turbo eventually, and if I only have to do the exhaust once instead of twice then I'm actually saving money and then I just crank the boost when I get a standalone ECU someday

 

Can we hear some good audio clips of a few 6k pulls...purty please???....

 

Enticing first sentence of post: DYNO TIME!

First off, installed an exhaust on Saturday that I had laying around from a different vehicle.



Then went for a 70 mile drive up the mountain and back down and it ran like an absolute charm and is a complete blast to drive!

Anyways, today I went to my neighbors work and we dyno'd it because why not





And the graph:



160hp and 160ft-lbf. This is the first time I've ever been on a dyno, and that is the "corrected" number which I guess is what people compare with. The actual power at elevation was about 125hp/tq.

This is pretty pointless besides a baseline, so right now the truck is 125hp and weighs ~2300lb with no one in it. The one weird thing was the rev limiter was around 6200rpm and it should be at 6800rpm. I don't know if there's some other weird stock ECU thing turning it down. Im not going down that rabbit hole much since it runs completely normally otherwise, but is odd.

I'm also now back to debating just spending the $2k on the cheap turbo kit but I should stay focused on getting good seats and redoing all the wiring so it has lights and stuff...

 

You mentioned the 70 mile drive and my internal voice wondered if you had the doors on it yet....

scroll

scroll

scroll

Yep!

 

I got my seats in today!

These and then paint the truck TRD Inferno orange and black it out, ooooh it'll be sexy!



And since we're here some updates. I changed the brake pads since they had an awful squeak. The Hilux pads can be changed without pulling the caliper which is nice.



I bought some door panels so got those installed.





I added some derpy little temporary brake lights, and also hooked up the headlights to the high beams and amazingly all the headlights work! I gutted the entire stock wiring harness, every single thing. I plan to rewire it, which is really just horn, turn signals, headlights and brake lights, wiper motor, and blower fan. Everything else is mechanically controlled, so not much reason to try and salvage the stock wiring.

I ended up entering the truck in a car show for the hell of it it was by far the derpiest thing there, but probably was in the top 5 of the most fab work, which is why I figured it'd be fun. I like custom stuff, and old cars I think are cool but if you can buy it then that inherently puts it behind any custom work in my opinion. So it looked janky, but to the right person maybe someone at the show thought it was cool next year it'll come back looking super sexy too





And then mainly what I've been working on the past few weeks is this stupid thing:



This is the truck that the previous owner of the Hilux bought the Hilux for to scavenge the bed off of to fix this things bed. He had been waiting for some welder dude to splice the beds together, and I kept pestering him I wanted the bed sides and finally offered to just do it myself. Which was a BIG mistake. I thought he wanted like 2ft to be spliced--no he wanted the whole bottom replaced. I retardedly said sure, even though this is like a $2000 job. But hey I get "free" besides out of it and they won't be hacked up! Yesterday I finally finished prepping everything for welding and got it tacked up.



Hopefully have it all out of the shop within a week. I only work on it a few hours here and there, so don't think I'm spending all my time on it. I have the bedsides now:



And that wraps up all the photos. I've driven the Hilux probably a few hundred miles so far. We take it out a few times a week, really most things in town we use it like lunch or hardware store runs. It's still running like an absolute champ, though I think it burns some oil. Once I get the guys pickup out, I plan to work on the interior. Mount the seats, install the carpet and sound deadening, and wire everything correctly. The dude also gave me a bunch of parts he found like tail lights, which mount on the bedside like a tundra so once I get the bed sides mounted I'll be able to use the stock tail lights. I'm pretty busy in August so not much will be happening until September.

Here's two fun little clips from some testing flying with my drone while the wife was driving the other day, in the future I'd like to make a cool little video but until then:

https://youtu.be/lUC2_gk0wCo

https://youtu.be/croF61GbP54

 

The cool thing about taking it to the car show like that, is when you bring it back next year all pretty people will say "remember what that looked like last year!?".

 

Just something tangential:

 

@Voss

 

It's time again for some updates fellow Hilux and/or 2JZ followers! Last update was July 30th, hell yea Not much happened through the end of the year, drove the truck around a bunch and then I was traveling a lot, did some work on the buggy, and then winter hit. I got insulation quoted in November (finally) and that involved moving everything outside or into a corner of the shop, and then they weren't able to get around to actually insulating it until a week and a half ago. So nothing happened whatsoever in the shop from about Thanksgiving to 10 days ago.



And then immediately after that I had some friends from SLC come down to work on their 4runner in preparation for KOH in a few weeks. They helped me move stuff around but organization was the extent of working on my stuff.



The shop also has a new layout, and I added a second mini pallet rack. Everything is located along the outer perimeter so there are no tables or anything in the middle, which opens it up and makes it WAY more spacious. As you can see we stuffed 5 vehicles in with room around them all and space for a few more. After everyone left, this is the current setup:



And first project up is the Hilux! I got a letter months ago that they wouldn't send me the title until I got a safety inspection since the title is from Oregon originally. Really dumb considering it's plated, registered, insured, and legally fine to drive. With that said, it won't pass safety because it doesn't have a horn or blinkers since it didn't have tail lights. So the first task is to finish the bed sides.



I had started on one side awhile ago and hadn't touched the other side at all. The one side was tacked up and that was it. I don't know if it was mentioned before, but the truck was a long bed and for the best I can tell was a short bed frame (probably one and the same frame) so the bed overhung the frame a lot. I had gotten used to how tiny the truck was without a bed, and wanted to keep it really small looking, so that started with how to mount the tail gate, which bolts to the bed originally. I made some mounts for the rear cross member (rear fuel cell cross member) and that left about 4" of the frame hanging past the tail gate, so I chopped that off. The tail gate location set the length of the bed sides which meant I had to remove 13". As you can see I made the cut behind the wheel well.

My plan was to use some alignment fins that I'd weld to both pieces to create a level plane for both pieces. The first bed side I tacked the sheet metal and then went to weld the fins, which ended up not working great. The second side I did all the tacking on the fins first and that worked much better (I ended up cutting the sheet metal tacks on the first side, but still didn't end up going as smoothly).



With the fins welded, I welded the sheet metal together which was a complete bitch as you can imagine. I welded the inside, and if there was anything weird on the outside I welded over it.





I then took the flappy disk to it. I honestly thought it'd turn out better, but the sheet metal got so warped during the process I'll have to follow up with Bondo. But that's a task for another day (or year )! Speaking of Bondo, the passenger side with the fuel filler has a metric ass load of what I think is Bondo? But the metal seems perfectly fine on the inside, and just has like a 1/4" of Bondo on the outside. I'm wondering if this was from the factory to form the body around where the fuel filler cap goes? The body appears to have similar quality on the B pillar in a few spots. I can understand it getting crunched, but the fact the bed side where it's just painted metal on the interior of the bed side shows no signs of being crunched, I'm kind of confused. Regardless, it's cracking.



Onto mounting the bed sides. I decided to keep it simple with a bracket off the roll bar that goes to three bolts on the front of the bed sides, and then make a bracket to go to a hole at the rear of the bed side.





This whole setup is actually surprisingly stiff. I need to drill a hole for the second bolt in the rear, and I think I'll add some stiffening elements to the beside itself so it's pretty floppy without the floor now, but otherwise I'm very happy with it.





And that brings us to the first time the truck has looked like a truck!









There's a bed piece that goes behind the wheel well, one side is crunched pretty bad and the other is fine. I could cut both at an angle and make them a pie shaped piece, I'm not sure if that or just leaving the piece off will look better. I could also add some wings onto a rear bumper like off-road bumps are. Speaking of which I need to do a rear bumper, and depending how that turns out I may raise the fuel cell. Right now the top is flush with the top of the frame so I can have a mini bed area, but with how far it hangs below the bed looks a little weird. It'd be easy to raise it, just cut four welds and reweld the fuel cell cradle, but then I'll have less mini bed space (hell at that point just skip the mini bed since it wouldn't be level with the frame or tail gate then).

But the main goal of having the tail lights mounted so now I can start wiring those in is complete! The bed sides will get more work, but I'm happy with how it's looking right now! And now that the shop is insulated and I have some little (soon to be big) heaters, I can actually work on stuff in the winter without hating life

 

Not sure if I'm more jealous of your skills or your workspace! Both absolutely rock!

 

Heck of a build!! Many hours and lots of fun!! I can’t believe the amount of time and resources involved! Very nice job! I was able to get my reading up to date.