2LT-II into Auto LJ78 (1 Viewer)

[GTSSportCoupe]

Since I bought my truck, the rear two cylinders have had a bit low compression. This is due to the previous owner in Japan letting water sit in the rear cylinders back when the head went. It rusted and pitted them. I was able to drive it fine since I bought it, but now the damage is starting to catch up with the engine and it's using some oil. The pitting is bad enough, I don't want to even bother boring it out and rebuilding.

Anyhow, deal came up on an excellent condition well maintained 1990 Hilux Surf with a 2LT-II (mechanical injection) with R150F. So I bought it.

Plan was to swap everything over from my 2LTE to the 2LT-II short block, and install into the LJ78. I've now just realized that the 2LT-II has no ability to mount a crank position sensor. The casting is there, but no hole to mount the sensor. So I'm considering moving to the mechanical injection.

I'm wondering if it's possible to retain the electronic Auto transmission with the 2LT-II? Will it still work ok? Or will I have to manual-ize it?

Thanks for any ideas. I'll start searching/reading as I think I saw a thread about this in the past too.

 

[GTSSportCoupe]

Found a comment from way back. Sounds like maybe just the TPS signal is needed for the transmission to work right. Can anyone confirm? How about tach signal?

We have done 3L conversions to replace the POS 2LTE.

The TPS hooked up is required for the trans to shift properly. If not there, the trans pressures may run up and the shifts may be hard and late. The TV cable needs to be hooked up.

Make sure there is a line going to the boost compensator on your IP from the same place that the line from the MAP sensor used to come from. If the BC is not getting pressure from the intake, then you will have very sleep performance.

If the hoses are hooked up, then you may need to add some fuel - either at the main fuel screw (try 1/8 turns at at time) or at the "smoke" screw on top of the BC.

I really dislike the 2LTE - and I can only hope that the engineer at Toyota that proposed this electronic design was forced to commit harakiri with a dull and rusty katana (and no, that's not bad karma on my part).


~John

 

[JimmyPrado]

If anyone can do this, my money's on you! There's more acronyms in that explanation than half the governments in the world. Good luck Nick. (Following)

 

[kbushnz]

Should just need tps and Ground speed.
Here in NZ the guys put on manual pumps into to 1kz units. Leave the ecu in to run the auto. And it works. Might throw some error codes. But who cares. Throw in yah new engine with manual injection and give it a go. You just need a way to retain tps. Backup is manualise auto.
From memory the lj78 has a stand alone tcu.

 

[GTSSportCoupe]

Should just need tps and Ground speed.
Here in NZ the guys put on manual pumps into to 1kz units. Leave the ecu in to run the auto. And it works. Might throw some error codes. But who cares. Throw in yah new engine with manual injection and give it a go. You just need a way to retain tps. Backup is manualise auto.
From memory the lj78 has a stand alone tcu.

Thanks again kbushnz! Really appreciate all of your input. I'll give it a go. The 2LT-II engine I got actually has a TPS on top of the injection pump (used by a simple emissions computer that controls the EGR I believe). So hopefully I can use that TPS. I'll dig out the schematics for both the Japanese 2LTE Prado and the Euro 2LT-II Prado and compare to make sure.

Friend of mine is a machinist and offered to drill a hole in the block for the crank position sensor. But I'm guessing it would be something that would need very accurate placement to give the right signal. According to ToyoDIY, the 2LT-II shares the same crankshaft as the 2LTE, so it might work. Probably not the best option though....

Only reason I'd try to keep it electronic is I had just bought/installed a brand new Injection pump this Spring. (I stumbled across for sale on gumtree in Australia - someone who did not even know what it was). It's going to be painful to sell that with only 5000kms or so that I put on it. Oh well.

I guess the mechanical pumps are generally more desirable anyhow? Guess I'll give it a re-seal before I put the motor in too. Engine runs perfect, so I'm assuming the pump is in good shape.

 

[Postoy]

Wishing I had some input since you are always a wealth of knowledge. Following, excited to see how your make out.

 

[Diesel Cruiserman]

It was a long time ago when I did the 3L install, it shifted way to early..what info does the transmission ecu need for proper shifting points?

 

[GTSSportCoupe]

Probably going to drill the hole for the crank position sensor at this point. Pretty sure the 2LT-2 crank has the readout bump on it, but if not I'll use my 2LTE crank.

I did also look into the transmission wiring. And as discussed, looks like it just needs the TPS signals (IDL and VA) from the engine. The transmission control unit is a separate thing from the engine control unit (as kbushnz said), although they do share the TPS signals. In fact, the VA signal seems to go through the ECU before it goes to the TCU.