Unintended Acceleration (in a Volvo)

Thought I'd share.

In the fall of 2006, I was driving back to the city on the Eisenhower (290) at about 5pm. I was driving a 1989 Volvo 740GL Wagon (B230F) at about 160,000 miles. I was traveling at about 50mph.

Here is about where I was when it happened:
[ame=http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=chicago+il&sll=37.0625,-95.677068&sspn=38.775203,77.958984&ie=UTF8&hq=&hnear=Chicago,+Cook,+Illinois&ll=41.874386,-87.713299&spn=0.008915,0.019033&t=h&z=16]chicago il - Google Maps[/ame]

The situation was slightly unusual for me, in that I was in the second to right hand lane, when I would normally have been in the left or second to left hand lane.

I was letting off the gas after going over a small hill when I noticed that I was still accelerating. The pace of acceleration was slow at first, but then the engine stuttered/misfired maybe four or five beats and the pace of acceleration increased. This whole process lasted about four seconds at the most from the time I noticed that I was not in control of the throttle until I decided I *really* needed to slow down and popped the shifter into neutral. The throttle remained open, so the engine immediately redlined, some sort of governor kicked in, and the RPMs wavered between... well, as high as they go, and really close to about as high as they go. It sounded like "REENENENENENENNENENNENENENE".

At this point, I'm going about 60 in neutral, in traffic, on the highway, with the engine redlining. It's been about 7-8 seconds since this started.

My father had always warned me about letting the engine stay anywhere near redline for more than a second. I quickly turned the engine off, as I was in neutral, this would have little effect, which was fine, I didn't need to slow down any more at this point, I just didn't want to be in traffic.

So, again, to review, It's been maybe 9 seconds now, coasting in neutral, engine off, probably back to 50mph, still in the second lane from the right.

So I coast for a little while, thinking about what to do, and eventually decided that if I turned the engine back on, and it freaked out again, I could just as easily turn it OFF again and just coast onto the shoulder.

I turned it back on and it was fine.


Never happened again, car lasted to 204,000mi.


A quick thought. I feel like the loss of control over the throttle is SO unsettling that it makes any acceleration at all feel like the car is really rocketing forward and is completely out of control. It was really just like flooring the pedal, but the adrenaline makes it feel stronger. Take that into consideration when you hear about other cars "lurching" forward.