DANGEROUS unwanted full throttle situation

Hi people.

Im not sure wether this should go here or on tech but seeing as more people may see it and it may be of interest to a lot of you Ill put the thread here.

Ill set the scene first, the car had been running for about five minuites poodling along at about 30 going around a few roundabouts in town, I get to the last big one heading off down a duel carrageway.

all of a sudden without me pressing any harder the car seems to jump up to full throttle, I had to jump on to the brake to keep it down to about fourty. Luckilly just at the start of the duel carrage there was a layby, to bring the car to a stop I had to push VERY hard with both feet with the car still on full.

Luckilly I managed to stop the car before the end of the layby, I moved the auto to N there was a jerk and the car dropped back to tick over.

Switched off, checked everything, nothing obvious, started up and drove home in manual (dont know why just felt safer), I have tried it an hour later by myself, in auto no problem.

As you can imagine this was a bit of a scare and Im pretty concerned that this may happen again at a worse time.

My car is a uk BPU auto and I had a 1st decat, fuel cut defencer and boost controller fitted about 5 weeks ago and done about 800 miles over that time.

Any ideas or any knowledge on this would be greatly appriciated.

Cheers.

Bob

It is the standard mechanical throttle isn't it? Not fly-by-wire?

BTW, in crash investigation circles this is called unintentional acceleration, and has been known to cause a few deaths.

http://www.leftlanenews.com/nhtsa-launches-investigation-over-another-toyota-product-with-unintentional-acceleration.html

Just bulk standard apart from above mentioned.

throttle pedel stuck under the floor matt? dont see how it could revv on its own unless ya cruise control is having a shit fit?

Could the throttle body its self got stuck open maybe a bit of s**t got through the filter and jammed in the system or maybe you throttle cable is rusty inside the plastic causing it to stick like a cycle bike cable does sometimes. not sure just firing a few ideas here.

Hmm if it was a sticky throttle cable, then it wouldn't have "jumped" to WOT. very odd...

I know what you mean but no was only doing 30 ish so peddle no where near floor or mats. although I never thought of that I wouldnt have thought it was the cruise.

No, checked all cables and they are spot on everything clean and free moving.

Cruise control to me seems like the most likely cause of the problem...

The accelerator pedal didn't move when this happened did it?

Would cruise control go onto WOT? My dad's doesn't lol.

Did you try putting your foot on the accelerator fully then taking it off to see if there was a difference?

Idle control valve had a fit??? Went to fully open?

Could pull quite a bit of air through it.

Idle control valve had a fit??? Went to fully open?

 

Could pull quite a bit of air through it.

forgot about that. My ex gf's ka did this and i had to replace that very valve

Would cruise control go onto WOT? My dad's doesn't lol.

 

Did you try putting your foot on the accelerator fully then taking it off to see if there was a difference?

No I didnt, didnt think off that and Im pretty sure the peddle didnt move.

Idle control valve had a fit??? Went to fully open?

 

Could pull quite a bit of air through it.

Would this be enough to give WOT?

i dont think it would to be honest!!! are you sure you foot just didnt put it all the way down and your brain just forgot

Would this be enough to give WOT?

No, but at 30 (throttle basically almost closed) it would probably flow enough to give significant acceleration. What ID is the bypass? Anyone know?

i dont think it would to be honest!!! are you sure you foot just didnt put it all the way down and your brain just forgot

Not this time but it has happened before, like leaving toddington services in a convoy on the 22nd and not even getting past the fuel before putting it up a bank, oh and ending up facing the wrong way looking back at 40 other supras with everyone staring.

Bob.

My car is a uk BPU auto and I had a 1st decat, fuel cut defencer and boost controller fitted about 5 weeks ago and done about 800 miles over that time.

Wild stab in the dark, but the problem may be linked to some of this stuff that you had done.

Who did the work?

Cruise control to me seems like the most likely cause of the problem...

 

The accelerator pedal didn't move when this happened did it?

I'd subscribe to this....

It's happened to me, throttle full open wit me standing on the brake to stop me power sliding into many immovable objects!

Turned out to be a loose bolt on the cruise control wossit.

Someone else reported this a while (perhaps years) ago. I cannot find the thread though...

If if was hard to brake then you can rule out an idle control issue. There's no way it can draw enough air to get the sort of engine power you describe.

It sounds more like either a CC or throttle issue.

If if was hard to brake then you can rule out an idle control issue. There's no way it can draw enough air to get the sort of engine power you describe.

 

It sounds more like either a CC or throttle issue.

Yep, fair point there. Brakes can usually absorb more power than the engine can produce.... but having to stand on them to slow it sounds like it had gone WOT.

I think someone's already asked this, but did the accel pedal sink to the floor?

It just really sounds like what I had. WOT and the rest! Have a look at your throttle thingmy dood. Give it a bit of a wiggle and see if owt moves.

i has the same problem, turned out that a piece of the inside of the rubber hose connecting the i/c pipe to the TB, had gotten free and got sucked into the TB and stopped the butterfly from shutting (ie stuck in WOT).

Am I right in thinking the auto can just be knocked into neutral in a TT while on the move, would save trying to stomp on the brakes if that ever happens again.

I know my NA auto could be accidently put into neutral if i were holding the shifter.

Doesnt sound good, knocking it out of gear could possibly help in this situation.

Not this time but it has happened before, like leaving toddington services in a convoy on the 22nd and not even getting past the fuel before putting it up a bank, oh and ending up facing the wrong way looking back at 40 other supras with everyone staring.

 

Bob.

Can I suggest you don't drive the car until you find the problem. Rip the car to bits if you have to. It would be very sad if you killed yourself or someone else as a result of this serious fault.