2005 LX 470 - Seemingly random brief lack of acceleration from stop (1 Viewer)

[RedMD]

I purchased, approximately a year ago, a relatively clean 2005 LX 470 from auction (CarsAndBids) with 120k miles. Since then the only real issue I've had with the vehicle is a seemingly random brief lack of acceleration from a stop. It happens maybe once out of every 10 times I drive it. I put my foot on the accelerator and nothing happens for a fraction of a second then it feels like something "engages"/"catches" and I get acceleration but it's an abrupt launch.

I'd appreciate any help in figuring out next steps. I've had the computer scanned by a trusted mechanic but nothing came back abnormal.

 

[FxFormat]

Impossible to diagnose problems that happens randomly, but if I had to guess, throttle/accelerator position sensor could be the issue.

 

[RedMD]

Would you expect that to be the issue if when I press the accelerator my RPMs increase but I have no forward motion for that fraction of a second?

 

[GTV]

Would you expect that to be the issue if when I press the accelerator my RPMs increase but I have no forward motion for that fraction of a second?

If the engine responds but the vehicle does not then the problem is likely downstream of the engine. Confirm trans has enough ATF (check for leaks), inspect the u-joints and CV axle/hub splines.

I believe I've felt what you're talking about but it happens so rarely that I just chalk it up to being some sort of glitch.

 

[OEMGUY0720]

So it goes to limp mode (ecm pushes this mode to prevent catastrophic damage to your engine) and I assume after you turn the ignition off and start it again it’s back working like nothing happened? And no check engine light after the restart?

 

[RedMD]

If the engine responds but the vehicle does not then the problem is likely downstream of the engine. Confirm trans has enough ATF (check for leaks), inspect the u-joints and CV axle/hub splines.

I believe I've felt what you're talking about but it happens so rarely that I just chalk it up to being some sort of glitch.

I'll check all these and get back to you. Thanks for the recommendations.

 

[RedMD]

So it goes to limp mode (ecm pushes this mode to prevent catastrophic damage to your engine) and I assume after you turn the ignition off and start it again it’s back working like nothing happened? And no check engine light after the restart?

This is something that will randomly happen at some point during a journey, not at the beginning or end. It will only happen once. I don't have to turn the car off and back on for the behavior to go away. I've not had it happen twice on a single drive before.