HELP!? Sudden Acceleration
Team Owner
Joined: Sep 2003
Posts: 20,176
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
There are pics on this board of a cracked booster shell that was only visible from underneath.
Advanced
Joined: Jun 2012
Posts: 56
Likes: 0
From: San Ramon CA
The original poster said the car ran fine at the dealer so any huge vaccume leak theories are out the window. Second you need fuel to go along with that air and if the TPS is not reading a higher opening the engine will get no more fuel.
Take the car out, turn the cruse control on and see if it happens again. If it was me I would just turn the ignition off but not all the way so I could still steer and coast to a safe place to park if it's not the cruse.
Take the car out, turn the cruse control on and see if it happens again. If it was me I would just turn the ignition off but not all the way so I could still steer and coast to a safe place to park if it's not the cruse.
Instructor
Joined: Jun 2012
Posts: 249
Likes: 0
From: Alabama
I have seen this happen, but it was the floor mat that slide forward and pressed the gas pedal. Check your floor mat and make sure it isn't loose. This can also explain why the dealer didn't find anything wrong.
Also, if this happens again just put the car in neutral. That way you keep the power steering/breaks and you have time to safely stop the car.
Also, if this happens again just put the car in neutral. That way you keep the power steering/breaks and you have time to safely stop the car.
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
I have seen this happen, but it was the floor mat that slide forward and pressed the gas pedal. Check your floor mat and make sure it isn't loose. This can also explain why the dealer didn't find anything wrong.
Also, if this happens again just put the car in neutral. That way you keep the power steering/breaks and you have time to safely stop the car.
Also, if this happens again just put the car in neutral. That way you keep the power steering/breaks and you have time to safely stop the car.
Safety Car
Joined: Sep 2010
Posts: 3,752
Likes: 190
From: Indiana PA
Advanced
Joined: Jun 2012
Posts: 89
Likes: 3
From: Zimmerman MN
Sara, if your still reading these replies, I have a question for you. Beings your car is an auto, did it downshift when this happened? If so, then I would say that the throttle body had to have physically opened. This could happen if the cruise control module malfunctions and pulls the throttle open.
Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
just my opinion. a vacum leak will need fule to raise the RMPs like the op stated. the throdle would have to almost have to be pulled or pushed Ir by foot or cruise actuation. lost on a couple of things why did you not just turn the key to off or put the car in nutral. Imlike the floor mat deal the best..
Advanced
Joined: Jun 2012
Posts: 56
Likes: 0
From: San Ramon CA
This post got me to thinking and I took my 87 out on the freeway to try out the cruse since I have never used it in this car and it has a BBK throttle body. Guess what the cruse did not seem to work then I forgot about it being on and ten minutes later went up a slight incline and the car shot up to 100 plus before I got the switch turned off on the cruse.
It was not WOT but it was mashed pretty good to go from 80 to 100 before I knew it. I am sure my problem is the heavy spring on the BBK throttle body making the actuator for the cruse to push too hard.
I should swap the throttle body and runners back to stock since the tune is off anyway. There is a big hole in the fuel map at mid throttle, it runs good crusing and wide open but not mid way.
It was not WOT but it was mashed pretty good to go from 80 to 100 before I knew it. I am sure my problem is the heavy spring on the BBK throttle body making the actuator for the cruse to push too hard.
I should swap the throttle body and runners back to stock since the tune is off anyway. There is a big hole in the fuel map at mid throttle, it runs good crusing and wide open but not mid way.
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Team Owner
Joined: Sep 2003
Posts: 20,176
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
The original poster said the car ran fine at the dealer so any huge vaccume leak theories are out the window. Second you need fuel to go along with that air and if the TPS is not reading a higher opening the engine will get no more fuel.
Take the car out, turn the cruse control on and see if it happens again. If it was me I would just turn the ignition off but not all the way so I could still steer and coast to a safe place to park if it's not the cMruse.
Take the car out, turn the cruse control on and see if it happens again. If it was me I would just turn the ignition off but not all the way so I could still steer and coast to a safe place to park if it's not the cMruse.
Team Owner
Joined: Sep 2003
Posts: 20,176
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
