Reducing the reliability of a first gen Tundra (01 2wd->4wd S/C Build)

[smokeysevin]

My second throttle showed up and I got to work dissecting it. My initial thinking was that I would just do a motor comparison and see where that got me as far as motor spec and control.

Stock Tundra throttle body

Tundra APPS, everyone assumes this is a cable driven throttle but that is just a sensor with a "limp home funciton" on it. If the sensor fails, you can get 20ish percent throttle if you go WOT with the pedal. We can mount the APPS sensor wherever, its big and annoying in the engine bay.

Jumping over to the drive side, the gearbox, motor, TPS, and motor clutch are in this gearbox.

Splitting the case gives you this, the motor and clutch are there in the bottom, and the dual TPS is up top.

On the other half is an integrated shaft, min/max throttle stop, and the gears as well as the tps fingers (nut and lock washer removed already, no proof)

Then I took the range rover throttle apart to see what if anything could be transferred. Start by drilling out the 6 rivets and popping the lid off.

Under the lid is a digital, hall effect/prox probe type sensor for the tps and the motor contacts.

Nylon/glass fiber reinforced gears, the motor, and throttle stops.

With the gear removed you can see the motor mounts and the gear a little better.

Motor removed, nothing special.

The gears mesh but the ratios are wrong, the stock tps on either setup would clash with the gears and the net result would still be not great. I went to sleep dejected.

Sean

 

[smokeysevin]

I woke up itchy today and had to go to work. Then at lunch I broke out the portaband and cut a big chunk out of the Tundra throttle. I ran out of time at lunch but came home and did the sketchy manual mill (a router with a carbide bit and some 1-2-3 blocks as spacers) to flatten the butchery out. Then I put everything back together and came up with a plan.

Now I just need to design a bearing retainer to hold the second bearing in place on the face, and make a shaft coupling to hold the Tundra shaft to the new TB shaft and mount the gearbox to the new TB.

Sean

 

[DP_Tundra]

Tundra APPS, everyone assumes this is a cable driven throttle but that is just a sensor with a "limp home funciton" on it. If the sensor fails, you can get 20ish percent throttle if you go WOT with the pedal. We can mount the APPS sensor wherever, it’s big and annoying in the engine bay.


The 99-02 tundras had a cable throttle, 03-06 were electronic. I’m still not sure what it is you’re doing here but I enjoy the science!

 

[smokeysevin]

Its not a cable throttle. It lools like one but its not actually driven by a cable. Ill take a video this week to show how that works.

Basically the stock 01 Tundra throttle body doesn't fit the tvs supercharger, I made an adapter using a cast elbow but I don't like how it fits. I need the stock throttle body motor and tps so the stock ecu doesnt freak out like it did with the electronic controller. So I am taking the motor, gearbox, and tps and setting them up to drive a new throttle body that does fit.

Sean

 

[DP_Tundra]

Ahhh gotcha! So what’s the difference between the 99-02 and 03-06 throttle bodies if the cable driven one isn’t actually cable driven? Im curious to see how that works.

 

[smokeysevin]

Ahhh gotcha! So what’s the difference between the 99-02 and 03-06 throttle bodies if the cable driven one isn’t actually cable driven? Im curious to see how that works.

Basically, the 99-02 mounts the accelerator position sensor on the throttle body and that accelerator position sensor is connected to via a "throttle cable" to the pedal. The accelerator position sensor has a little arm on it that can open the throttle slightly if the ecu freaks out but its only ~10%.

The 03-07 setup uses a separate accelerator position sensor in the cab. There is no physical connection from the pedal in the cab to the throttle body at all.

For my purposes, I had hoped that since they are all yota parts, they would just swap. That ended up not being the case which led to me trying to trick the stock ecu with signals that made the out of range stuff run in range for the stock ecu. The problem was that the new throttle motors didn't respond the same way as the stock motor. From there I went meathead and just said screw it, Frankenstein mode engage.

Sean

 

[DP_Tundra]

That makes 100% sense, great explanation.