Hi,
Today I was taking my 1994 Corvette out for a drive. I drove it out of the garage and put the brakes on to allow me to close that garage door with remote and to fasten my seat belt.. While I was fastening my seat belt, the engine accelerated, and the car took off at a high rate of speed. It took me by surprise, and I wasn't thinking. I was focused on not hitting anything. The brakes wouldn't stop it no matter how hard I pressed on them. I hit the gas pedal and as soon as I did the car slowed down. I drove it a few miles with my hand on shifter so if it did it again, I could immediately put it in neutral. While I was driving, I noticed that the cruise control was on. I shut it off and drove the car several more miles and did a few errands. It didn't happen again. Could the acceleration I experienced been caused by the cruise being on or am I looking at something else? Has anyone ever experienced something like this? Does anyone know if Chevrolet ever did a recall on an issue like this? Appreciate all replies.

Thanks,

Daca55

 

Wow. I wouldn't have driven the car anywhere until I found the cause of that terrifying ****. The brakes wouldn't stop it but the gas pedal did? Check for a broken motor mount.

 

Audi has experienced this.

Are you sure, sure, SURE that you didn't stab the gas pedal why trying to get the seat belt on? That's be my guess. No, the cruise wouldn't likely cause that.

 

Im positive I never hit the gas petal until car took off and then I hit it.

 

...

 

My foot was on the brake pedal when I came to a stop after coming out of the garage and then the car took off. I understand somewhat your technical expertise but this actually happened the way I said it. It’s not BS.

 

My ZF combo did the same thing;-) just know like the Twilight Zone.
Next thing✓ i knew my shifter automatically went from 1st - 6th, then Reverse = RACE like a bolt of lightning. Honest guy's;-) then My ASR spooled- up should have heard that wastegate. Whistle. aka "slip limiter". went Helter Skelter WOT. wheel took over started doing donuts and everything. Just like Maximum Overdrive. Remember Uhhhm.. And then. Wake- up! Thank You! That's my story✓ I'm sticking to it. So there!

 

Well then....start investigating. Let us know what you found.

 

DO NOT tamper. Trailer this astray auto driving C4 to GM. See if this car enters the Genniuss Book Of World Records.

 

I will and I will let you know!

 

...

 

I had a 92 that would surge during driving from time to time. A few times as I'd come to a stop it would start to raise in RPM and want to go, then would come out of it. I tried replacing the idle air control valve first, which does electronically bypass the cable driven throttle body. This did not resolve the issue though. I ended up sending the ECM to SIA electronics and had it gone through citing issue with the IAC. Once the ECM was returned the issue never returned. It was very unsettling when it would happen. Not sure if this helps but I thought I'd share. Good Luck.

 

Thanks for sharing! It’s good to hear from someone who also has experienced the same issue I am having but sorry it happened to you cause it is scary. Bare with me but can you tell me what ECM stands for and what is SIA electronics? I have owned this car for 20 years and this is the first problem I have encountered so not familiar with abbreviations and terminology.

 

My car has only done it when I was stopped and in drive with foot on the brake. Never done it when I was moving. The optispark is the original as far as I know unless the previous owner replaced it.

 

I don’t get it. Brakes should have been able to overpower and tapping the accelerator would have done nothing based on the description.

Option 1:
- Foot on brake
- fiddling around in car foot either slides off brake onto accelerator or pushes both
- foot pushed harder to “stop”, going WOT
- foot removed from accelerator and accelerator “tapped” seeming to stop the “crazy” behavior
- brake properly depressed, rest of drive normal

There is no way I can see “tapping” an untouched accelerator pedal doing anything.
- Runaway cruise control? Tapping pedal would not disengage (try this with cruise control engaged)
- runaway IAC…maybe disheartening but should easily overridden with brake pressure…and tapping pedal should not have fixed it… the IAC is not going to go full throttle…it can’t, right?
- crazy optispark? How high of an idle? It sure would not run properly as the throttle plates would still be closed, no way enough power to do anything with brake applied


Option 2:
- foot stayed on brake the whole time
- car went “nuts” and went full throttle (only thing that has the physical ability to move the throttle this far is the cruise control)
- brakes were unable to overpower the motor (see jeep Cherokee runaway lawsuit proven false due to pedal misapplication and fact brakes could overpower if actually applied)

the cruise control would have to:
- be enabled
- ignore minimum speed
- short circuit to think it should be “engaged”
- ignore brake switch
OR go into an unknown crazy failure mode independent of all other factoea

I’m not saying there is a 0% chance something happened here, but if we are talking WOT I don’t see it.

 

Thanks for your input. After the car stopped accelerating I noticed that my cruise switch was in the the on position. This has happened to me a couple of times. The other time it happened I had just pulled into a parking spot and put my foot on brake to stop and then the engine started to accelerate. That time I was able to stop with brake and it stopped accelerating. Yesterday that wasn’t the case as acceleration was much greater.

 

Final thing I’ll say, is test it.

go to a safe area.

setup car exactly as you had it (car in gear(reverse or forward), foot on brake.

take your other foot and floor it and hit brakes full at same time or even with a slight hesitation.

what happens? Feel the same?

 

at WOT, there is no manifold vacuum...so CC can't physically get the throttle to WOT.

 

Any floor mats in this car?

 

I was thinking the same thing. The only thing is yesterday when it happened I had started car in garage and drove it out and came to stop and it was in drive with my foot on brake and while I was fastening seat belt it started to accelerate and took off.