[madmarchhare]

So now I have had to calm down, Anyone else experienced this?

I had the occasional surge sitting at the lights 500 to 1000rpm and back a couple of times (no, I do have a witness so I wasnt imagining it).
Now today, merging into traffic on the local highway, I have my 2 1/2 yr old son in the back, and I have to accelerate hard to miss a loser who doesnt know how to change lane, and the Jeep STICKS at WOT. It was 100mph, crossing 4 lanes to miss the cars and barrier before I was able to get it to shut off.
I thought, my car mat had got stuck on the pedal, so I threw that out !!
well, it drove fine for a few miles, got off the highway and stopped an McD's for a calm down, and left again. This time, goining the traffic pulling out of McD's, again, WOT and 2 lanes of stationary cars at the lights. I managed to turn the key and burry the brake pedal (virtually through the floor).

Checked everything i could and drove EXTREMELY carefully and dropped him off at daycare, and its been fine since.
Please tell me im not the only one experiencing this.
I am thinking dirt in the plasic throttle pedal assembly, or a screwup on the ECM or sensor?

[chadhargis]

I've not heard of it on a Jeep, but Audi had a major law suit back in the 80's concerning unintended acceleration, and my brother had a Saab that had the same thing happen. Luckily he was on a wide open interstate. He simply turned off the key and turned in back on to solve the issue.

That's one of my big fears with anything that's "drive by wire". I am an IT Manager for my company, and I've been working with computers for 27 years. Believe me, I know they fail, and fail regularly.

Most of the systems in cars are simple logic based systems. They take a reading from a sensor or potentiometer and apply an action based on a pre-programmed table. The logic part is fairly bulletproof, it's the sensor or potentiometer that is the problem. If it goes bad, and gives a false reading, look out!

[tomlennon]

best guess: electrical problem with motor in throttle housing or possessed child. no codes thrown?

[madmarchhare]

Originally Posted by tomlennon

best guess: electrical problem with motor in throttle housing or possessed child. no codes thrown?

Ah, I see you met my son already...
No seriously, i got down under the dash, and didnt realise the whole assembly is plastic.
My guess is probably dust in the Pot (potentiometer, not the drug type).
I will baby it home tonight, and hook up the big scope to it and watch the trace,
anything "iffy" would show a jump on the trace

[tomlennon]

I understand what you're saying, but it may be difficult to replicate the problem. I'm not sure if it's a pot or an encoder...either you'll get ohms or a step waveform on your scope. Could it be as simple as you accidentally activated the cruise control? I'm actually thinking that it could be mechanical, where the throttle doesn't swing closed.

There's always the conspiracy theories, too:
http://autocoverup.com/

[madmarchhare]

Well, as I mentioned, i HAD experienced the "surging" before at a stop Light.

......Come to think of it, he was in the car then Too !!!!!!

[BlueSteelJP]

I would get rid of the POS, kind of like a family dog biting your son-you shoot it dead, your family comes first.

[chadhargis]

A friend of mine had a pit bull that went crazy and attacked a family member. Luckily, her dad was a police officer and happened to have his gun on.

Dog dead.

[colinzj]

Originally Posted by madmarchhare

I am thinking dirt in the plasic throttle pedal assembly, or a screwup on the ECM or sensor?

If the Jeep system works like most systems (and it probably does since everyone's using the same crap anymore), sensor's unlikely. Drive-by-wire usually uses multiple sensors to confirm the input.

Heck, it could be as simple as carbon buildup in the throttle body.

Also: Next time, please use neutral. That's what it's there for—playing Frogger on the highway or turning off a vehicle that isn't at a complete stop is asking for a one-way ticket to the Pearly Gates.

[Jeep Brian]

Originally Posted by BlueSteelJP

I would get rid of the POS, kind of like a family dog biting your son-you shoot it dead, your family comes first.

X2, that thing has to go! No way that would be home in my garage, right to the dealer for a trade!! I wouldn't let your wife near that thing!

[TRZ]

Originally Posted by colinzj

Also: Next time, please use neutral. That's what it's there for—playing Frogger on the highway or turning off a vehicle that isn't at a complete stop is asking for a one-way ticket to the Pearly Gates.

Agreed - everyone should have a plan for this, just in case. Several years ago in Denver a woman was driving a rental moving truck when the accelerator stuck full throttle. She didn't think about putting the truck into neutral and literally ran into rush hour traffic (some guy actually saw her plight and tried to slow her vehicle down with his car - to no avail).

[madmarchhare]

Putting it in Neutral is actually advised against (I have read this many places and had confirmed by a couple techs.) and they recomend turning the engine off, (not removing the key).

Also a 5.7 goes from 60 to 100 in less time than you realise. So honestly, until it happens to you,, please dont judge others.

I decided that it was safer to take avoiding action than put others lives at any more risk than they were already at.

Now Just because its done it this time, doesnt mean that its a bad dog, I need to find out why it did it and fix it, then it will probably be safer than yours. At least i know what "may" happen, having experienced it first hand and will be more prepared should it do it again.

My post was intended for feedback to see if anyone else had experienced this (and the "mythical surging problem")

[MGPenn]

if it is auto, check the tranny fluid, i had a nova that did it to me years ago. tranny fluid was low, tried to pass a card and passing gear kicked in and the tranny could not build enough pressure to let the passing gear disengage. stuck WOT till engine turned off. scared the crap out of me. i dont understand it but dad explain it to me when it happened about 15 years ago.....

[Mills]

Originally Posted by madmarchhare

Putting it in Neutral is actually advised against (I have read this many places and had confirmed by a couple techs.) and they recomend turning the engine off, (not removing the key).

Also a 5.7 goes from 60 to 100 in less time than you realise. So honestly, until it happens to you,, please dont judge others.

I decided that it was safer to take avoiding action than put others lives at any more risk than they were already at.

Now Just because its done it this time, doesnt mean that its a bad dog, I need to find out why it did it and fix it, then it will probably be safer than yours. At least i know what "may" happen, having experienced it first hand and will be more prepared should it do it again.

My post was intended for feedback to see if anyone else had experienced this (and the "mythical surging problem")

I don't think anyone is judging you, rather pointing out a rather standard procedure for negotiating a wide-open stuck throttle. Everything I've ever heard or read dictates to do just as TRZ says. I'm curious now, though. Where did you read this?

[bbanger]

Originally Posted by chadhargis

I've not heard of it on a Jeep, but Audi had a major law suit back in the 80's concerning unintended acceleration

FYI it was operator error. 60 minutes had to mention that they were wrong in one of the episodes due to that. It almost killed Audi as a company.

Vehicle was equipped with heel/toe sport pedals and they were not as common in america as in europe so many people didnt know how to drive with them.

I work for Audi as a service advisor and have to explain this a lot