I have a Tacoma. I said I had a tundra. What’s the big deal?
Let’s see, t-u-n? Nah. It’s t-a-c? Spelling is hard.
I have a geo metro, ugh, I mean I have a Ferrari. Got distracted.
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Alright alright… You got me in such a troll…
Okay, enough bashing of the OP.
My guess ECM is failing, but would expect an illuminated CEL.
$90 diagnostic fee is below what is charged in most areas that I am aware of. IMHO a proper diagnosis is the most economical way to deal with this truck.
Had I known the OP had a Tundra instead of a Tacoma, I would have asked if they have tried cleaning the electronic throttle body?
Tester
I basically said that 9 days ago.
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just a thought, have you checked for vacuum leaks? a vehicle that old is bound to have dry rotted or cracked hoses.
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I know what it is now. It’s the throttle.
The throttle coil isn’t engaging the throttle plate until it’s about 50-60% turned so it’s not opening the plate all the way up.
I can open the plate 100% with my hands w/o the throttle being connected and turning it open where the throttle would engage the plate but not with the throttle.
This is as far as the plate will open with gas pedal pushed all the way to the floor.
This is the throttle plate when turned about 50 or 60% of the way
Follow the cable, it goes into a threaded rod and a nut. you may be able to adjust it. but it seems your cable stretched
Yep, good investigative work there. And that certainly explains the symptoms. Problematic throttle actuators not an uncommon topic here. Forum search link (upper right this page) might provide some ideas on best way to rectify the problem.
IAC valve or electric throttle actuator, semantics in diy’er parlance.
The thing is I’m confused because I have a drive by wire…
What exactly does the pedal position sensor do?
The accelerator position sensor sends a signal to the ECU, which then operates the electronic throttle body.
Tester
So is the gas pedal suppose to open the throttle plate by itself when the gas pedal is fully compressed?
Or is the ecu/ecm suppose to send a signal to open the plate electronically based on the pedal position and the gas pedal not suppose to open the plate all the way?
Full disclosure, just a driverway diy’er, I’ve never owned a vehicle w/that configuration. But my understanding is a computer reads the pedal positin sensor to determine how much the accel pedal has been depressed by the driver. Then the computer commands the electric throttle actuator to move the throttle valve (located in the throttle body) correspondingly. For example if the driver pushes the pedal 15 degrees , the computer will read “15 degrees” pedal press, then will command to throttle actuator to open the throttle valve proportionally.
You probably recall the incidents of claimed unintended acceleration in newer cars a while ago. To address this problem many of the current systems use a bevy of redundant sensors, whose reading have to match, otherwise the computer will place the engine in limp mode.
I’m looking at the cable and I don’t see much room for slack. The thing I’m confused about is when I turn the accelerator pedal position spring by hand shouldn’t it open the throttle plate regardless of the throttle wire?
Also when I put the pedal to the floor the throttle body sensor spring seems to be fully turned.as if the throttle cable is not stretched out
In a drive-by-wire throttle actuator system, I’d be surprise to see a steel cable running from the accel pedal to the throttle body. You might see a bundle of wires for the sensing and actuating signals. I guess it’s possible for such a system to be configured so there’s a steel cable from the accel pedal to a sensor in the engine compartment.
sorry, I did not re-read the post. I thought you had a regular throttle cable.
Yeah if you look at the pictures you’ll see a cable connected to the sensor it has a spring that can turn and it turns the throttle plate without the ecm because those pictures are with the battery disconnected.
It just doesn’t open it all the way. I don’t know if it’s suppose to be like that.
With the car on ifeel more power in the pedal. It throttles loud as soon as press it during idle so I know the throttle plate has to be opening.
But when I drive it operates just like how I described it like the throttle sensor isn’t engaging the throttle plate right away and it’s not opening all the way up. it the rpms don’t increase immediately when I press the gas (very subtly though)
I see what you mean. I’m afraid I’m beyond my pay grade on this one, like I say I’ve never owned that configuration before. I did have a problem with the throttle valve function on my Corolla (cable-actuated) one time. I removed the throttle body and a bench-inspection showed me what was wrong. You or your shop may have to try that approach, as it may be difficult to figure out what’s wrong with the throttle body still mounted on the engine.
I am not familiar with your vehicle, but on some vehicles the computer will relearn the TPS. on others there might be a procedure to do it like the following. but Tester will probably know the answer to that.
Well the one thing I can say is that after cleaning the throttle body the rpms are a little closer to normal. Not normal though
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