Explanation for Toyota Accelerator sticking

Long before the recent Toyota recall, I heard a caller asking about the fact that her Toyota gas pedal seemed to “stick” and required extra pressure to accelerate from a standing stop. I, too, had that problem and realized there was a vacuum lock causing the sticky gas pedal, not a cable or accelerator mechanism as you “chumps” asserted. My '96 Rav4 has 210,000 miles, has had one voluntary gasket change, and no other problems whatsoever (routine maintenance, of course.) Oh, yes, I did jiggle the battery cable once when it didn’t turn over, then bought a new battery and cable connector. I think the earlier models are exempt from the recent accelerator problems involving uncontrolled engine acceleration. They should go back to their earlier design for accelerator configuration.

The “chumps” to whom you are addressing the message do not contribute to this forum.

They NEVER go back. That’s not how the system works…

Please explain the vacuum lock. I have never run across a Rav4 with a vacuum accelerator.

What is a vacuum lock and where did this vacuum lock occur?

Yeah, I want to know what a vacuum lock is.

I have heard others who say their accelerator “catches” and requires a hard push to engage. I, too, thought it was the cables or some mechanical component sticking. When I pushed the accelerator, to overcome the “catch,” I would get undesired power for a brief moment. When I inspected all the cables and mechanisms leading to the action controlling the intake (air intake at the front of the manifold), I used my hand to open the vane closure. That is when I realized it was not a mechanical component that was sticking, but rather a vacuum inside the manifold that caused the vane/closure to be reluctant to open.

We are told: "Simply put the car into neutral then turn the engine off."
MAY NOT BE SO SIMPLE! Check out these video clips:

(after putting car in neutral and unable to turn off engine!!!)



and the CA crash:
“911 Call Released from Crash that Prompted Initial Toyota/Lexus Floor Mat Recall”
(with California Highway Patrolman driving unable to stop vehicle)

"Witnesses saw flames coming from the front and rear tires of the speeding 2009 Lexus ES 350 before it crashed Aug. 28 in Santee, suggesting ?long, constant heavy braking,? said Sgt. Scott Hill, the lead sheriff’s investigator. "

That doesn’t really answer anyone’s question. There is supposed to be vacuum inside of the manifold. It isn’t going to keep the throttle (“vane closure”) from opening.

More likely, the problem is that Toyota routed the PCV valve to connect right behind the throttle plate and therefore the backside of the throttle plate gets covered with an oily sticky mess that causes the throttle plate to stick closed, leaving that feeling of extra pressure required to accelerate from a stop (gotta apply extra pressure to crack the plate open).

It was so common that my Haynes manual for my Camry printed the year after my model came out already warned of this problem.

Well, the CAUSE of the sudden acceleration might not be simple. Indeed, there might be several causes (including driver error). However, coping with it – if it happens (still rare) – IS simple: shift to neutral; steer to safety, and turn off the engine.

You seem to be confusing the complexity of the diagnosis with the simplicity of the proper reaction. Your logic is flawed.

I think this is a better explanation.

This thread started almost a month ago and I’ve yet to hear an explanation from the OP about what a “vacuum lock” is.

Just consider me one of those “chumps” who doesn’t get it until it’s explained to me.