OK drove my previously functioning 2000 Sienna, it was driving fine/like normal for a minute, then it started "lurching" when I hit the gas. Felt like it was losing power or starved or something, it couldn't gain speed...in idle it would still "rev" a bit (lose power), though less. Like "power, die, power, die, power die"

More clues: the battery light was on (but only dimly LOL) and so was weird other lights like ABS. No check engine light. Also previously (a bit) sometimes the dash lights would flicker with the engine RPM

After hooking a charger up to it, it started up (surprisingly), and ran well for a minute, then started lurching and finally ground to a halt (despite amount of gas pedal). It couldn't get much speed going. Not to mention dying eventually.

Battery read only 8v DC across the terminals (using a voltmeter). I went ahead and charged the battery, turned the engine on, and it ran but the voltage for the battery didn't go up to the 14v like it should when running, so now I suspect the alternator. If I put a voltmeter on the alternator "output" terminal and the other lead to ground, it would show 1.5v. Weird, it should show 14...

1 Answer 1


Resolution: Went to remove the old alternator (since the alternator at least wasn't providing power), and the connection to the alternator itself snapped off with some krinkly ashes in my hands (guess it was supposed to have a cover over it that had been removed and it had since corroded). Got it re connected there (new crimp connector) and battery reads 14v now when running. Seems the alternator was good, it was the connection to it that was "starting to flake". Based on my internet research seems other causes of the problem can be the mass flow sensor or the tube that feeds it etc.

My hunch is that the lurching (when idling it's almost like "revving" but not high rpm's, from normal to low, and back) means the battery is driving the spark plugs solely (no help from the alternator) and the battery is near depletion. If you can make it to Autozone you can test things out there, if not you could pull parts and take them in separately to autozone to be tested.

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