Stuck at full throttle

Sounds like the throttle cable slipped off something and jammed at WOT.

 

I'd be curious about the condition of the throttle cable. I was considering to sell my old one from an 83 but when I pulled it out, I tossed it when I noticed that it was starting to fray at the end near the pedal. This was an 83 car so I wonder if an 86 car would have seen similar wear.

It seems that this is a part that is often replaced and I could imagine a scenario where the frayed ends jammed at WOT.
Whether or not this happened is another question entirely. Someone else can comment as to whether or not this primitive ECU had a rev limited based on cutting fuel and/or spark.

 

I would have someone sit in the drivers seat and push the accelerator pedal down while you inspect the movement of the wire in the engine bay. The cable runs under the car and up into the air intake manifold belly. Its a simple wire inside a metal sheath and it is visible from the engine bay. Inspect for proper movement up and down. It has a spring in the engine bay to return it to idle. Maybe the spring broke?

 

Lou:
Other will have to comment on the idley position on the engine as mine is already sold and didn't live long in my car.
I was commenting actually on seeing fraying at the OTHER end (in the footwell). You can access it by lifting up the center carpeted tunnel part

 

Yes that is the spring and it should be pulling the throttle all the way back to idle.......Have you had the fuel distributor serviced recently?

 

Hello Lou,

Sorry to read that story, but I had two different cars stuck on full throttle as well but in both cases no damage for doing the only right thing:
TURN THE IGNITION OFF !!
I know it is too late for your engine now, but I hope to help others that read this:
First car was an 1978 automatic and on a nice country road. Pedal felt loose suddently and as it was rear wheel drive and no ABS car, forcing the brakes would have had me spin out for sure. Putting in neutral would have surely overrevved the engine, hence after checking my options I turned off the ignition and let it roll to a hard shoulder. Thank god for that experience because:
Second car was a 321hp Mcoupe that I flored in 2nd gear in the city. It had just come out of service where they lifted the full carpet for some wiring and the pedal just went to the floor and stayd there, although it felt completely normal before. Had I not know what to do from the first experience, I do not want to imagine what could have happened there.
The reason for the pedal in the M to stay down at full throttle was very simple: There is a bolt in the footwell that limits the movement. For the mechanics having forgotten to put this back, at a certain point the pedal flipped over the assumed dead-point and now the spring assembly actually held it down !

It is a rare default, but it can happen on any car even with an electronic accellerator if the pedal is held down by something, so I hope your and my story will help save lives and engines.

Safe driving,

Mondi Cab

 

I urge everyone to remove any driver-side floor pad - just have the glued carpet.
SG


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There is little doubt that you have found the problem. The cam needs to come to rest against the adjustment screw for idle. Without that happening the engine will just speed up. As to why....most likely it is a cable or spring issue.

On to the bigger question of why won't it start. Click Click Click is not a broken engine. When an engine is locked up.......it makes one hard thud as the starter tries to turn the flywheel. First thing to do is push the throttle lever back to the stop.

My hope is that you have a battery problem as a result of the traumatic incident your son encountered. What typically happens is that the car ignition, lights or flashers are left on which drain the battery to the point that it has insufficient charge to turn the starter. Put the battery on a charger and let it charge up. My money is that it will start. As to pushing on the accelerator or driving it......that is a no until that throttle rests on the adjustment screw every time it is moved.

As to what happens when it starts......it will probably be okay. If it is running rough some of the valves might have been bent but that is easy to check with a compression or leak down test. Older engines are far more tolerant of over revving than most people believe.

Give your son a big hug. This was not his fault and I'm sure he feels terrible.

 

My floor mat was pushing HARD up against the throttle...and it took me a few days to catch that.

I felt dumb, but better dumb than dead!

 

The only caveat I might add to this advice is to remain calm while switching the ignition off and have the presence of mind to not turn the ignition too far and lock up the steering wheel while at speed and possibly get into a crash.

 

No, it shouldn't be there -- it should be against the stop screw when the gas pedal is not pressed. Disconnect the acc. cable end from the ball on the gold throttle plate mechanism and determine whether the problem is in the cable not returning (floor mat, pedal mechanism sticking, popped strand on the cable hanging up somewhere inside the sheath) or the throttle plate mechanism itself (when the cable end is disconnected, the throttle plate mechanism should move to rest against the stop).

 

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I'm wondering if it is possible to damage the engine simply by overrevving. When this happens it's usually when one misses a shift -- downshifting from 4th to first instead of third, say -- so that the momentum of the car, transmitted through the transmission, forces the engine to rev more than it would be capable of on its own. I guess flooring the engine without any load isn't good, but I wouldn't assume the worst. And maybe your son wasn't absolutely flooring it when it stuck. Let's hope.

 

If the engine has the nuts revved off it, have a look to see if the belts have not jumped off or jammed up the pulleys

 

I see the glued blond carpet in the picture, but I also see the black mat - which isn’t glued, of course. I urge everyone to get that mat out of there.

[Every single Toyota sold today has the pads latched down on top of factory carpet. The pads are dangerous if loose. ].

I understand light colored carpet NEEDS a pad to help keep the factory carpet clean. Find a way to secure the driver’s side pad down so it will not slide forward.

[For the originator of this post: ask your son whether he pulled the pad away from accelerator at any time.]

Best,

SG


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But what you did not see is the addition of the angled aluminum I riveted on so the black carpet can not rise up and fits snug underneath the addition

 

Good luck with the situation Sir. SG


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A condition I've observed on mine is that the throttle cable hits the underside of the package shelf. It hasn't caused a problem, but it did have wear on it that made me nervous and I wrapped in electrical tape. If you take the inspection cover off behind the rear seats, it comes up in the middle behind a small steel angle. Mine seemed to be binding--the loop, not the throttle-so I arranged it as best I could and wrapped the flat spot in the rubber casing so it wouldn't wear through. I could see this becoming a problem, though.

I did have a throttle cable on a different car wear through and short out across the battery when I was in High School, which melted it down in a big cloud of foul smelling smoke. Makes for a funny story at least--the girl I was making out with looking into my eyes and saying "I think your car is on fire..."

Just thinking of this since I sometimes let my 17-year old son drive the car. It's great that you're sharing your passion, and accepting the fear that comes with that.

Best of luck!

 

X1/9 throttle stuck twice. Turn ignition off as soon as possible. Scary stuff