Passing gear hesitation

I have an 02 dubcab v6 and have been experiencing hesitation when I go into the passing gear on the highway. Anyone experienced the same with yours or any ideas...

 

I'm not familiar if the 02 has a transmission kickdown cable at the throttle body. If it does, over time the cable can develop a little slack in it. You can remove some of that slack by loosening the nuts and adjusting the cable tighter.

 

hesitation as in engine hesitation or trans not downshifting when you expect it to?

 

That's not a kickdown cable. That's line pressure. The transmission is controlled by and ECU. We need more info on what kind of "hesitation" you are experiencing.

 

The trans downshifts but then engine hesitation. Think of a turbo diesel when you punch it and the speed kinda hesitates while turbo spools, similar to that just without the turbo lol...wish I had a turbo!

 

The trans downshifts but then engine hesitation. Think of a turbo diesel when you punch it and the speed kinda hesitates while turbo spools, similar to that just without the turbo.

 

When was your last engine tune up ?
Have you ever tested to see if your catalytic converter is starting to plug ?

 

I did Toyota oem plugs and wires about a year ago. No I haven't tested the cat, how would I do this?

 

If its a late 2002 and happens to be drive by wire. It's normal. Mine will kickdown but throttle doesn't open as fast as my foot steps on it. Motor will increase power in a smooth curve. As of you were rolling on the throttle.

 

Is there a fix for this?

 

No

 

How long has your truck acted up ? or is this something that has been with the truck since you owned it ?
There is an aftermarket gadjet called pedal commander . Not sure how well it works
https://www.tacomaworld.com/threads/pedal-commander-does-it-work.460981/

https://www.tacomaworld.com/threads/sprint-booster-throttle-accelerator.178829/

 

I've never seen one for a first gen yet.

 

This is true . Just figured because it was drive by wire that there may be some hope .

 

I pulled this from another site...


As it turns out the Accelerator Petal Position Sensor Assembly is the issue. This is the plastic assembly at the front on the Throttle Body to which the Accelerator Cable attaches. Though the 03 has a cable it is not intended to regularly directly control the throttle's position but rather it turns potentiometer that then changes a voltage that is applied to the ECU's electronics indicating the potion of the pedal. The ECU uses that data turn the Throttle Control Motor and engage its clutch, which actually opens and closes the throttle.

The throttle has a catch at 90 degrees into which an arm on the Accelerator Petal Position Sensor Assembly fits but this arm is at about 60 to 70 degrees, not contacting the throttle. This is normal. It is so that if there is a failure, one can still mechanically control the throttle somewhat.

The Accelerator Petal Position Sensor Assembly has a shaft onto which the lever for the accelerator cable is mounted with some return springs. This shaft also turns the potentiometer. This lever (a plastic piece) limits the travel of the assembly, so the highest and lowest resistances of the potentiometer are not encountered in the potentiometer.

The problem is that the potentiometer can also turn in the assembly, loosing its reference to the arm and lever. Then the range of resistance that is possible can be changed. If it turns too far one way, the higher resistance will be such that there is not sufficient voltage sent to the ECU to indicate that the pedal has been depressed. Conversely, there is a point at the other end of the petitioner where the full voltage is applied and the ECU sees this as a failure and closes the throttle by releasing the Throttle Control Motor's clutch. My case was the former.

By removing the Accelerator Petal Position Sensor Assembly, removing the springs and nut, and leaving it connected to the circuit with the ignition on, I could use the lever to turn the potentiometer to beyond its and reposition it. While doing so I was listening for when the Throttle Control Motor's clutch to engage to position the potentiometer so that occurred near the start (the stop to which the springs turn it) of the assembly's travel.

Now it runs fine. In fact the throttle response is the best it has been in a very long time. I believe that the potentiometer was likely moving a little bit occasionally over months and months and on the trip to Las Vegas it had moved to the point of becoming a real issue.

Will it continue to do so? I think it'll need a new Accelerator Petal Position Sensor Assembly all the same. find me one!!!!???

I also think the design of the Accelerator Petal Position Sensor Assembly is flawed. Carefully using an ohmmeter I could see positions in the potentiometer that may be questionable. This may be do to vibration wear or dirt and may cuase issue at some point. However, more important is the fact that the potentiometer's position is not secured well in the assembly. When I experienced loss of power is was always in the desert in rather hot air (105+). Could the increased temperatures cause expansion in the plastic and loosen it?

Anyway, that is where it stand today . . . seems to be good for now and I'll look into more after I get a few other tasks done, like find a new job! <G>

 

OP hasn't confirmed he's drive by wire. He has an 2002.

OP does your cable side of your throttle body is there a 4 wire plug. I'll find a picture.

 

Does yours have the circled part?