Power loss on right curves

Hi: I’ve got an '05 Tacoma 4WD with 145,000 miles. Very recently, when taking right curves at moderate speed ( e.g. freeway cloverleaf onramps), I’ll lose power at the apex of the curve. It comes back immediately when the I straighten out. No warning lights on panel. It feels like no gas since there’s no difference when I press the accelerator pedal.

Anyone have any ideas?



Does the level of gas in the gas tank make a difference?


Doesn’t seem to. It happened today at 1/2 full though when I first noticed it, it was below 1/4. Today, I was coming uphill and accelerating. The other day, it was a downhill cloverleaf turn onto the freeway.

Then the problem might be with the fuel pump/strainer?



Have your front end alignment checked too; especially the idler arm. With a steering box you should have that part.

How fast are you entering the curve? It almost sounds like the vsc is activating. If you enter a similar left curve will it act up?

Probably about 40 on the uphill curve, closer to 55 on downhill/cloverleaf. What’s a vsc??

How would steering box/idler arm affect this? I’m pretty clueless with cars, especially anything that doesn’t have a carburetor… .

Thank everyone for great suggestions! I’ll take them in to local shop and see what they think. I’ll post fix if/when it happens.

Vsc is vehicle skid control. I am thinking the ecm is thinking the truck is entering a skid and reducing engine power. Try the same curve 10mph slower and see what happens. If it acts normal, I would reset the zero point and go from there.

Steve: ah, good idea. If that’s true (and I think it is because the same type of curve at slower speeds don’t seem to trigger the problem), is that something your average shop can do or is it a Dealership thing.

VSC is a possibility that I hadn’t considered, but it could be the source of the problem.

Then again, Tester’s suggestion regarding the fuel pump/strainer is also a strong contender.
To his theory, I want to add the fuel pick-up in the tank as a possibility.

More data: I started thinking about fuel and fuel filter. When I’ve had problems like that before with other vehicles, they would sputter and, as a result, jerk. In this, it just cuts out totally, then resumes smoothly. But, so far, hasn’t happened on left curves.

VDC: yes, thanks for that too. I’ll just go down with a list from you guys. Mucho thanks!

I would second the fuel filter problem if that has no been addressed. The other thing is the traction control and VSC sensor which cuts the throttle with excessive motion. Check your manual and see how to completely disable it (on some models it means pressing and holding the Trac off button for three seconds) if the truck does then not loose power when you take a curve, that is the problem area. The last area is the fuel pump pressure itself.

These are all great suggestions, but since it loses power 100% and then gets if fully returned, you might also want to give the electrical system a good going over. It’s possible that you have a loose or corroded engine ground strap, battery post, battery cable, or other electrical connection. If your battery isn’t properly secured, that might even be a big clue.

You may have a faulty power connection going to the pump. Perhaps the fuel pump relay contacts or a connector pin problem. Try reconnecting all the connectors in the circuit to the pump and maybe replace or swap the fuel pump relay if there is another like it on the car. The trouble could also be with the pump itself.

+1 for #the same mountain bike.

My only question might be, if it looses it electrically, it would have to still be a fuel delivery problem as power to the ignition would stall the car. I would guess too that the check engine light would be going crazy. @cougar sounds about right.

Is this an automatic or manual transmission? If a manual, it could be stalling out during the turn, but start up again after whatever the problem is stops happening after it comes out of the turn. With a manual you might not even notice this stall happening, but with an automatic you’d probably notice and it wouldn’t always start back up again on its own.

I’m with the electrical-problem branch here, that what it seems to me. A cable or connector may be getting pinched during right hand turns. Did this happen soon after some work was done on the car, especially work that involved the engine or transmission mounts?