Help! 2006 Sienna LE lost accelleration/power in 4th gear - does this make sense?

[stevenmac2]

Hi Everyone,

2006 Sienna LE.

If you wouldn't mind reading the description of a problem I encountered on Friday 4/18/2008, I would appreciate it as I need to know if this sounds right or not:

On Friday, I was travelling with my family down the interstate (driving roughly 70 mph) as to when I noticed some slight jerking in the van and a sudden decrease in power down to 50 mps. It felt as if the pedal had no resistance and was having fluctuating power to the van. Eventually, as I kept pushing on the pedal, I felt as if I lost all power to move the van fowrard while in 4th gear. Luckily, I was able to get into the emergency lane on the interstate and nurse the vehicle off to the next exit 4 miles away while driving in 2nd and 3rd gears. The main issue was that I could press the pedal all the way down and the vehicle would just start to die out - no power. I didn't know if there was a transmission problem or a powertrain issue that had occured. This was just odd - the vehicle has roughly 16,000 miles on it at this time. The vehicle went into a "turtle mode" at that point to where no significant speed could be performed on the vehicle. The vehicle was then towed back in and they gave us a rental for the time being.

The dealership called this morning to say that they could not find any problems with the transmission. However, they did say there were a series of pending codes that related to misfire and oxygen code (a total of 5). They were leading to beleive or on a guess since they can't duplicate our problem, that there was water, debrie, or dirt that had passed through the injector and is now cleared - alluding to that there was a contaminated fuel condition. Since the computer did not retest those codes, no hard codes were written and a service engine light came on.

My biggest question is this - why would bad gas perform at 2nd & 3rd gears, but not at 4th? doesn't make any sense. It seems like it would have rendered those gears useless too.


Has anyone else encountered this problem? Does this sound accurate as to what happened? should their response be accepted?

If responses can be provided shortly before they call back today, it would be greatly appreciated.

Thank you,
Steven

[stevenmac2]

Nevermind, I was able to determine the problem.

Yesterday, the dealership calls to say that the van is ready and that they are unsure as to cause - basically, they drove my van for 50 miles, put fuel cleaner in it and left it at that saying they can't duplicate the problem.

While I had the rental van yesterday, I noticed that it gets better gas mileage than mine and seemed to have more power. I took it full throttle (pedal to the floor) to measure the rpms at a particular speed and thought I would measure it again in mine to see if I get the same indicator.

To be none, when I did this, the vehicle wouldn't go above 30-40 mphs! They never thought to test this vehicle a little more - I am just thankful I wasn't trying to merge onto the interstate with a semi coming right up - just a dangerous situation not having the power to accelerate away from something.

It turns out that the vehicle will not shift up and that it is either a fuel injector issue or pump problem that is restricting the flow of fuel to the vehicle. Since the flow is restrictive, the computer is keeping the vehicle at a particular speed.

Seems like they could have done a better job testing.