Throttle stuck on - near death experience! IS300 sportback - is this a common issue

ScottH01 · July 23, 2018

Hi all. I overtook some slow traffic at the weekend, and when accelerating, the throttle stuck wide open - car accelerated from 60mph and kept picking up speed (to over 90). I managed to jam the auto box into neutral, the engine screaming and redlining. I've always had manual cars before, so go easy on me, have never been in this situation. Called an AA man, who sprayed some WD on the throttle cable where it coils around at top of engine. He suggested I check forums to see if it's a known issue. Does anyone know what I can do / read, to make sure it doesn't happen again.

ps. accelerator wasn't stuck under car mat!

Farqui · July 23, 2018

Yikes, I bet that got your attention!

I presume you were able to kill the ignition as soon as possible right?

I once had a dip stick spin around and lodge under the mechanical throttle linkage which had similar results. Rather than select neutral I killed the ignition and pulled over sharpish. I seem to recall that the dip stick got bent out of harms way after that close call.

Good luck getting this sorted.

Zotto · July 23, 2018

In this evenienze the right move is ti presa hard brake, brake are stronger than engine.

Steve · July 23, 2018

I think you'll find its the mat got stuck under accelerator... seen it many times here. Even happened to myself once. scary, good job i was in a manual.

Edit: reread post. ok not under the mat. Are you 100% sure?

rich1068 · July 23, 2018

Scary stuff!

Am I right in thinking this car is new to you? Check around the pedal end of the throttle for any bodgery. There was a popular mod to "cure" what was supposed to a bit of a dead spot on the throttle at pick up from eg junctions.

https://www.my.is/forums/f62/is300-throttle-cable-spacer-350180/

Other than that I can't think what it could be. I've never experienced anything like it with my IS 300.

ScottH01 · July 23, 2018

Car is new to me yes (4 months). Haven't checked the pedal box area to see if anything unusual, will do this...Zotto - braking did beat the engine in terms of power, you're absolutely right, and I'm really glad it worked. One thing I didn't think about doing, (as too busy trying to stay alive!) was to simply turn ignition off - which would mean no power steering but prob the best way to deal with situation.

Farqui · July 23, 2018

...no servo'd brakes either if you kill the engine, so beware of heavy steering (good shout, my old car didn't have this) and heavy brakes.

But you'll be so pumped that it won't be a problem!

Ben01 · July 23, 2018

Never kill ignition in the heat of the action! BTDT. Sudden lack of brakes servo and power steering would kill you either, even if you pumped up by pure adrenaline... Only put tranny into neutral, it does not matter auto or stick, brake normally and safe landing on the shoulder etc. and next kill the ignition. Don't bother with red-lined engine, even if it will blow up it's much easier to find another engine than new leg or head or life...

Zotto · July 23, 2018

Years ago it happened more often with diesel engines.

Sorry for my previous post but writing with cell phone made me quarrel with orthographic corrector.

Ben01 · July 23, 2018

To bright the scary day, I would share my more funny than scary version of the problem above (scary one was big ford revs and vigorously flied into middle of busy T-crossing...).

Funny version was: early '90 I had very crappy small fiat with broken fuel gauge. One day I miscalculated the fuel and car stalled in the middle of small home town. I used couple of heavy words, as it was like a mile walk to fuel station, so I looked around and have seen familiar automotive "jack-of-all-trades" shop. Quick jumped into, "Hi, hello, gimmie bigger bottle of common paint thinner", jump out, filled the tank a bit. Some stranger passed by and looked what the hell I was doing with glass bottle, he turned head so much he tripped badly over the pav and hit the street. Bad for him.

In mean time, I was such a smart boy! I though like - "this is very light fuel, half a litre or so means nothing, is this enough to fill pump, carburetor and stuff? and for a mile to petrol station? maybe I put more". I return to the shop, "Hi again, gimmie one more bottle of thinner" - lady at register (owner and my neighbour) "Whats up? Did you break it?" - "Nay, I just filled my thirsty fiat, but I think maybe it is not enough". All customers, ladyowner, and her husband in back of shop were like choir "WHAT THE HELL?!". But who cares, I grabbed bottle, paid, jump out, fill the tank again, I have seen like five or six people watching me from wide windows of the shop. Wave on them, started the fiat with no trouble, and flied away with noise and power of small ferrari.

I flied thru town like mad bat, worrying if the two cylinder beast withstand this sudden power tide (and if air coolin enough), with fabulous sound. Quick to the station, to the pump, ignition off, and WHAT THE HELL this stupid tiny engine revs vigorously like normal... I jump out, open bonnet, in panic disconnect the main harness, engine of course does not care, revs pretty fine. The guys - clerks at the station (they knew my briefly, small town, only two stations) in awe carefully approached me and fiat, like hunters to the prey or doctors to the mental patient. In mean time I found the solution - rip out the plastic inlet on the top (looks sort of like beetle's one), and cover inlet by hand, engine sucked, choked and stalled. "WHAT WAS THAT?" the guy was "Last time I've seen anything like this with overheated diesel, but how is it possible with this gasoline crappy fiat??!!" - I was calm and cool "For me? Easy peasy thinner breezy, lets fuel this monster"...