Builds The Truck of Theseus (2 Viewers)

[littlevulture]

Yeah I think you’re right, the other side is probably going to be mostly cut and welded anyhow since the geometry is more complicated so if I’ll probably be blending welds out anyhow.

On that note I watched this video awhile back and since then I’ve been trying to keep in mind my goal with stuff like this should always be finishing the project…which seems obvious but really wasn’t. In this case I think I’ll fix it but there’s gonna other opportunities to accept functional solutions to keep moving forwards.

 

[aztoyman]

Is this a build thread or a support group??

 

[littlevulture]

So cutting and bending it was the fix. Best I can measure the final angle was 7.5°. I’ll probably throw a couple small gussets on there but it should still fill with weld and I can blend it all with the grinder. Last picture shows the misalignment, only 2.5° but very frustrating.

 

[littlevulture]

Getting close, need to tweak the angles a bit to get a slightly closer fit and fix the part that’s touching the case but I’m happy with how it’s looking right now.

 

[aztoyman]

That's STOUT and it still will look good.

 

[littlevulture]

Yeah it’s turning out beefy. I think if I eventually add a brace up front too it’ll be a good skid plate to protect the drivetrain…definitely a heavy part, probably at least 4 times the weight of the factory crossmember.

 

[littlevulture]

Just ran out of mig wire but I’ve finally got the crossmember in the right shape…the driver side was impossible to get lined up how I wanted. Finally I got it where it needed to live and tacked everything in place under the truck then pulled it for welding. Threw a leftover chunk of the 1/2” plate across it to hopefully keep it from warping when I weld in all the scores that I made so I could do the bends.

 

[littlevulture]

Finished the crossmember I was worried about warping but thankfully it bolted up just fine. The welds aren't the greatest but considering no practice in over 5 years I'm happy with final product. I'll finish cleaning up the welds and paint it later. Not sure what to work on next, I think I should probably focus on the TDI harness before I forget everything I already did when I disassembled it.

The whole assembly looks like it hangs down really low but its got more clearance than factory and also should protect the front output part of the case more than the factory setup did.

Passenger side has plenty of space for the future exhaust.

Drivers side clears the front output, its only about a 1/2 inch at those bottom two bolts on the transfer case so depending on how much movement the drivetrain has I might need to clearance the back of the crossmember a bit for those.

The front of the drivers side has plenty of clearance.

I added a plate to protect that little white nub on the bushing that hangs down.

 

[littlevulture]

Took some time today to clean up all the grinder dust from the crossmember build and get the workbench mostly dust free so I can mess with the harness.

Somewhere in the chaos there is a standalone harness, just need to figure out exactly what parts are needed.

 

[aztoyman]

It'll be nice to have a well laid out harness with only the wires you NEED and WHERE you WANT them.

 

[littlevulture]

It'll be nice to have a well laid out harness with only the wires you NEED and WHERE you WANT them.

That's the goal, when I did the 5VZ swap I paid for an adapter harness from Off Road Solutions which was great except I never actually understood the wiring and it kinda went all over the place.

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Unfortunately there isn't a lot of documentation on swapping the newer common rail TDI's so I might have to do it in 2 stages after I start working with a tuner. These engines are very tunable but I don't have that skillset; if I rough it out enough to get it running then I can hopefully start working through all the sensors with a tuner and slimming it down before finalizing it. I think there's a couple things to consider while I do this:

• Sensors/actuators I need to keep (the bare minimum for the ECM to run the engine)
• Sensors/actuators I should keep (extra things to monitor engine health)
• Sensors/actuators I should delete (stuff that doesn't really hurt or help to keep)
• Sensors/actuators I must delete (stuff that goes to equipment that no longer exists after the swap)

I'm also on the fence about fuses...it seems like a lot of the people who do standalone TDI harnesses try to use the fewest fuses/relays possible by combining fuses/relays that VW originally had separate. This seems convenient for routing and keeping the engine bay clean but I think it's probably not ideal for maintenance and troubleshooting in the future. I'm leaning towards replicating the VW fuse/relay architecture for whatever parts of the harness I end up keeping.

Anyone have thoughts on that?

 

[aztoyman]

I agree with your sensor/actuator logic. As far as the combined fuses and relays I probably would NOT combine them. I can see doing that with lighting circuits and such. I think combining some things to minimize/simplify could come back to bite you when something fails.

I think it could work for some people though. Depends on how you process things in YOUR head. I'd rather be able to definitively nail down which circuit has the problem rather than figuring out which circuit in this GROUP is the problem. But this is just how my mind works. You gotta do you.

 

[gnob]

i would make that fusing decision once you have a grasp on the system and diagrams. vw isnt really known for simple wiring so i probably wouldn't really follow them...
following Toyota, i don't see much need for more than 3-4 circuits.

 

[littlevulture]

i would make that fusing decision once you have a grasp on the system and diagrams. vw isnt really known for simple wiring so i probably wouldn't really follow them...

I don’t know that any modern car has simple wiring anymore, it’s all CANBUS and data lines going everywhere.

I had spent a couple days separating the engine harness from the body harness a couple months ago since they were loomed together in a massive mess and it was absolutely overwhelming at the time. Now that I’m just looking at the engine stuff it doesn’t seem too bad.

The left side of the table is stuff I’ll probably need to address, right side is stuff I think I can ignore for now, middle is the mess that I still need to detangle. The big plug at the bottom of the table goes to the OEM fuse box, I’m thinking about cutting the wires where they meet it to make sorting easier. There’s still another half of the harness on the engine but I think I can mostly leave that stuff alone.

 

[aztoyman]

Looks like progress at least. I don't know ANYTHING about this system. Will you be able to run the engine if the ECM isn't able to communicate with other ECU's it normally sees?

 

[littlevulture]

Short answer is yes, there's a couple guys in the TDI Swap FB group who have this engine running standalone, one is an XJ and the other a 1st gen Tacoma.

Long answer is it depends on what systems are missing and how they interact with the ECM. Keep in mind I'm stumbling through this learning as I go but in general I think the ECM doesn't receive too much data from the other computers. There are a couple twisted wire pairs (generally that seems to mean data) that went from the ECM into the body that got cut when I cut the harness under the dash so I could remove it. I don't remember off-hand what those go to but they might need to be tuned away. There's also the immobilizer which is tied to the chip in the key via the cluster and body control module, I sent the ECM off few months back and got that tuned away so hopefully I won't have problems there. The last big thing I know needs to be dealt with is the emissions equipment, the stock ECM will be very unhappy without that stuff.

There's a bunch of little things too, for example this engine in a Golf/Jetta came with a swirl valve in the intake that introduce turbulence in the intake air to reduce emissions. It's a little plastic butterfly valve and actuator that eventually will break, the Passat version of this engine didn't come with that so I can swap some intake parts around to remove it...but all the little things like that will likely cause the ECM to throw a fit if I don't have the sensor/actuator tuned out.

 

[aztoyman]

I'm REALLY appreciating my 52 Ford after seeing what some of you guys go through to get your projects going. My 3.4 swap wasn't that bad but could have been tougher if I didn't have a complete running donor.

I enjoy following along on these builds. Wouldn't want to do it though. I hope it works out like you hope it does.

 

[littlevulture]

Yeah the complete running donor makes a huge difference, that's mostly why I chose this engine. I had actually already decided on and started searching for a 2UZ donor to replace my 5VZ while keeping it somewhat simple and all Toyota. I've always been a fan of diesel swaps though so when my car got totaled I figured I had nothing to lose except my sanity so I bought it back to be my engine donor...

 

[gnob]

I don’t know that any modern car has simple wiring anymore, it’s all CANBUS and data lines going everywhere.

I had spent a couple days separating the engine harness from the body harness a couple months ago since they were loomed together in a massive mess and it was absolutely overwhelming at the time. Now that I’m just looking at the engine stuff it doesn’t seem too bad.

The left side of the table is stuff I’ll probably need to address, right side is stuff I think I can ignore for now, middle is the mess that I still need to detangle. The big plug at the bottom of the table goes to the OEM fuse box, I’m thinking about cutting the wires where they meet it to make sorting easier. There’s still another half of the harness on the engine but I think I can mostly leave that stuff alone.

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boooo canbus

 

[littlevulture]

boooo canbus

CANBUS is actually pretty cool on the engine/sensor side. I think auto manufacturers got carried away with how it’s integrated into every part of modern cars but on the engine side I should be able to pull super detailed realtime engine health numbers.

The big problem is outside of some basic commands that get pushed to the OBD port it’s all proprietary and specific to each manufacturer so it needs to be reverse engineered before I can do anything useful with it…