Hunting around for a replacement brick (Volvo) for the wife has had be driving a number of them with the rather infamous defective throttle position sensor. These are throttle by wire cars, and Volvo managed to get the sensors bad on the throttle blade part for a few years. The end result, throttle response gets progressively weird.
One car in particular was almost undriveable. Why? Because you never knew when the computer would decide to open the throttle. That's right, any number of times the car would suddenly leap foward as the computer opened up the throttle, all on its own. Made manuevering through the parking like quite entertaining.
No, the car never held the throttle wide open. But it would definately spike the throttle, sometimes hard, and for upwards of good second or two. You definately wanted to have the brake pedal covered at all times with this particular car.
Others would exhibit similar traits, or horribly laggy throttle. But none were as aggressively jumpy on their own as this one was.
Thought some of you might find this interesting, particularly in light of the threads we've had in the past regarding throttle by wire.
Sounds like it may be time to look for a different vehicle or make fixing it a requirement for purchase.
My wife's Solara seems to have a laggy throttle. I hate it. A different one we test drove before purchase (older and more miles) didn't do it.
That is my biggest complaint about my mazda2 (aside from no 6th gear) the short gearing, and drive by wire makes it seem like you've never driven stick before.
There are dead spots and sometimes you are just trying to turn left on a green light and you mash the pedal and nothing happens when you really need to be getting out of the way of the cars coming right at you, then it kicks in and you seem to have jerky throttle response in stop and go situations.
The LS 400, a 1999, is TBW and has a kinda laggy throttle especially off idle. I see an ad in Teh Mag for some gizmo that is supposed to fix that. The Elise, also a Toyota TBW but with a Lotus ECU, has zero lag. It's like a cable.
The LS 400 has both a throttle PS and a pedal PS, plus a cable. If the TPS and pedal PS get out of sync because of a loose cable, say, then the computer freaks out and goes into "super limp home mode," completely disabling the electronic throttle and letting the cable control the throttle, giving you at most about 1/3 throttle, or enough to hopefully limp home.
