Mitsubishi 4D34-2AT3B diesel swap into 96 FZJ80

[SuperHatch]

End of today's work. The fist pic is the valve cover after I painted it. The second is the valve cover installed, and the third is the new pump installed.

Tomorrow I'll put the injectors in, reinstall the fuel lines, figure out the throttle cable issue, and start on the wiring.

 

[Fromage]

Looking good!

 

[UZJ40]

Very nice build thread! Makes me want to go diesel even more...

 

[SuperHatch]

Got pretty much everything mechanical buttoned up today. The stock intake manifold needs to have a bung on the back drilled/tapped for a hose that goes to the boost compensator on the pump. The manifold is cast with the bung in place (this is where it is on the 2AT equipped trucks) but there is no hole. I drilled and tapped it and smoothed the surface so the copper crush washer would seal.

The final pic is where I left off for today. Tomorrow I'll button the last couple mechanical details up and the tackle the wiring. I already checked out the diagrams and have a plan of attach in mind. There are exactly 36 wires that need to be connected, so I think it should go fairly smoothly.

 

[Fromage]

LOL you definitely are a fast car guy
If you have any issues with wiring I have the factory wiring manual...

 

[SuperHatch]

Hahaha, what? You don't like my red intake manifold? I was goign to paint the compressor cover too but didn't get to it yet.


I bought the US factory manual to figure out the wiring and to avoid all uncertainty. I appreciate the offer though.




Oh yea, finished up the PCU (Prestroke Control Unit) wiring today, truck fired right up and runs great. I can't drive it because I am waiting for Safelite to come put a new windshield in... I had it pulled since it was cracked and I had some rust that needed repair. They're coming on Monday to put the new one in and then I can take it for a ride.

I can tell you this much, the truck sounds completely different. There is a "sharpness" (if that's the right word) to the injection sound now, the throttle response is drastically improved, and it actually smokes when hitting the throttle! (what a concept!)

I'm really looking forward to driving it...

....stay tuned.

 

[Dougal]

The crackle of a direct injection diesel running as advanced as it should be?

 

[SuperHatch]

The crackle of a direct injection diesel running as advanced as it should be?

I guess so?

There is no way it was a physical timing issue before... i literally tried every possible timing setting up to the max possible.

I believe either the pump wasn't delivering fuel at the proper pressure or the prestroke mechanism failed.

 

[astr]

FSM

Since both you and Fromage have FSM's, would one of you be willing to scan and post your manual here: Downloads Index - Page: 1. You've both broken new ground with your swaps and having the manuals posted would help those who choose to follow in your foot steps. Just a suggestion.

 

[Fromage]

Astr, we already have some electronic files that we've been using, I'll get them up soon.

Mine doesn't smoke much, but it will definitely puff out some black when you get on the throttle. I have been using it for plowing and if I floor it, it will leave a visible cloud for a second or so. However, I was following the truck with someone else driving and I couldn't make out any smoke at all at cruise.

Looking forward to getting your first drive impressions for V2.

 

[SuperHatch]

Honestly the trickiest part of this 2AT conversion was rigging up a TPS to the factory gas pedal. The 2AT equipped trucks have a pedal assembly that incorporates a TPS that is actuated via a control rod. I basically made this work with the stock pedal. The pictures are kinda self explanatory.

 

[SuperHatch]

The other tricky part is that the new ECU doesn't have a 5V output to power any sensors since none of the remaining sensors are powered. The Aisin TCU relied on the 5V output of the 3AT ECU to power the TPS.

Well I looked at the Isuzu Aisin TCU pinout and it showed a 5V output to power the TPS. This pin was blank on the Fuso harness. Well I added a wire to the corresponding location, and voila! 5V power... Wired this directly to the TPS and all is well.

There are only a few inputs the TCU cares about.

- Engine RPM
- Throttle Position
- Throttle PWM
- Vehicle Speed

This is all the TCU uses to determine shift points/behavior.

The Throttle PWM is referenced by the TCU only as a backup is the TPS fails. This is the only input that isn't connected to my TCU since this was linked to the lectronic governor in the 3AT pump. Without this connected I get no check trans light and the trans shifts exactly as it did with the 3AT pump and ECU.


I attached a pic of where I added the wire to the TCU to get 5V, and also a pic comparing the 3AT ECU and the 2AT Prestroke Control Unit.

 

[SuperHatch]

Initial driving impressions? Throttle response is greatly improved, and trans behavior is no different that before... read: works perfect.

The truck is quieter at cruise and idle, louder on throttle, and overall more pleasant to drive. EGTs are lower, power feels better than before. The 2AT trucks were rated for less power than the 3AT trucks, so I wasn't expecting a rocketship out of the box. With full throttle EGTs at 850-900*F, I'm confident I've got some headroom to play with that fuel screw. Let the games begin!!!

 

[Fromage]

Great news! That is amazing that the trans will work with the older ECM. And, at 900F you have tons of room to up the power screw, it's going to make a huge difference. On my 6BT, the difference between 900F and 1200F felt like a hundred horsepower. It was insane.

Also, the smaller ECU would fit a lot nicer in the glove box (where I put mine).

I got your PM, thanks!

 

[Wheelingnoob]

Great to hear this is working out for you. I like the idea of this set up so much more than the 3AT set-up. I looks like that ECU will fit in the stock location with some brackets now that would be very cool.

Looking forward to seeing how this responds to fuel adjustments as well as overall economy.

 

[SuperHatch]

Great news! That is amazing that the trans will work with the older ECM. And, at 900F you have tons of room to up the power screw, it's going to make a huge difference. On my 6BT, the difference between 900F and 1200F felt like a hundred horsepower. It was insane.

Also, the smaller ECU would fit a lot nicer in the glove box (where I put mine).

The ECU does fit much better now, but i still can't go back to an unmodified glovebox. The 95-97 trucks have a lot less space in there than the older trucks due to the airbag. I'm going to see if i can modify things a bit to get it all in there at some point. Its close, but not quite there.

I got your PM, thanks!

I had a fairly high level of confidence going in that the trans would work. The Jatco trans in the 2AT trucks is fully electronic just like the Aisin trans. Comparing the FSMs showed the same number of inputs and outputs as well, minus the PWM input in the Aisin trans. The fact that the FSM stated that the PWM was only used for failsafe operation was icing on the cake.

On the other hand... bold assumptions like that usually bite me in the ass, so it was nice to have one work out for once.

 

[SuperHatch]

Great to hear this is working out for you. I like the idea of this set up so much more than the 3AT set-up. I looks like that ECU will fit in the stock location with some brackets now that would be very cool.

Looking forward to seeing how this responds to fuel adjustments as well as overall economy.

Thanks! I'm glad this worked out as well as it did... added some serious cost to the bottom line, but no more than a pump rebuild would have and now i have some tuning flexibility.

 

[Wheelingnoob]

So does this mean its possible to get a 2AT donner and a A442F and associated electronics for the A442F and make this work? That would be apealing to me and a possible cost savings in the end. Would still need the A450 torque converter though I would think.

 

[SuperHatch]

So does this mean its possible to get a 2AT donner and a A442F and associated electronics for the A442F and make this work? That would be apealing to me and a possible cost savings in the end. Would still need the A450 torque converter though I would think.

If you get a 2AT donor, you will need the following parts out of the donor truck.

- Complete engine with all accessories (Cut the chassis harness with as much pigtail as you can for every connector)
- Prestroke Control Unit (This is behind the passenger seat against the back of the cab, the harness runs under the seat to the front of the cab, you can easily get 4' of harness if you pull the the carpet and cut under there)
- TPS (This is mounted to the throttle pedal and a bit of a pain to get out, cut a couple inches of wire with the plug)
- MUTIC (This is the timer that controls the glow plugs, not necessary if you plan on running a standalone timer, it is located under the passenger side glovebox and is mounted into the relay box)
- Fuel Cut Motor (There is a cable connected to the injection pump adjacent to the throttle cable, it runs around the front of the cab to an electric motor, this is how the ignition switch turns the engine on and off, again, cut some wire with it, you will also need a 5-pin relay out of the relay box to wire this properly)
- Boost temp sensor (this is mounted in the intercooler)
- Water Separator (Not needed if you upgrade to a Racor unit)
- Tachometer (Pull this out of the cluster if you want to make a hybrid tach like I did)
- End of throttle cable (You can cut this off of the Fuso throttle cable and swage it on to the Toyota cable, this is what I did, worked like a charm.)

Then you will need the following from a 3AT donor if you want to use a toyota A442F

- Bellhousing
- Torque Converter
- Valve Body w/ solenoids and harness
- Rear Engine Plate (Maybe, I didn't get a good enough look at the 2AT rear bolt pattern to confirm)
- Flex Plate (See above)
- Trans Computer with harness pigtails, or go standalone TCU which may be a valid option to get lockup at lower vehicle speeds



I'm sure Fromage will chime in if I missed anything.

 

[SuperHatch]

Further driving impressions...


WOOOHOOOOOOO!!!!!!!!!!!!!!!!!!


the truck now drives exactly like I expected it to. I don't know if the Prestroke unit had to go through a learning cycle, or if air was still working its way out of the injection pump, but after putting another 50 or so miles on it the truck is an absolute dream. EGTs are now around 1000*F at WOT, and 0-60 is gone in about 16 seconds. The real joy is the passing power now, the truck just downshifts and scoots. Absolutely no comparison to before... I love this truck now, simply amazing.