2003 stalling/electrical problem - ideas?

[milanotom]

For the last few weeks, my wife's 2003 Corolla (w/ about 110,000 miles) had been stalling maybe once or twice every few days. She'd be at a red light, and when she tried to accelerate, it would stall. Sometimes there would be a faint humming/buzzing noise (that seemed to come from the left side of the dashboard) before it stalled. Then, it got worse and would occasionally fail to start. I was in the car the first time it wouldn't start, and it was the craziest thing. With the key on, the car wouldn't crank, but the tach needed slowly moved up to 7000, the slowly settled back down. It also made a similar "dashboard" noise. and I couldn't shift out of park, even with my foot on the brake. On the next try, however, the car started and ran fine for the next couple of days.

Eventually, we brought the car to a local garage, and when they hopped into it, it wouldn't start again, but they couldn't figure out why. They had it towed to a local electrical shop, but once there, it started just fine. They couldn't find the problem, althought the thought the alternator wasn't charging the battery enough. We drove from there to a local Toyota dealer, and it's still starting.

I'm sort of amazed that this is stumping everybody. Nobody can recall it ever happening, nor can anybody explain why the tach moved on its own.

Dose anybody have any ideas???

Thanks in advance,
Tom

[mikered30]

No check engine light? Sounds like a bad ECU, although not covered by the new recall.

[milanotom]

Originally Posted by mikered30

No check engine light? Sounds like a bad ECU, although not covered by the new recall.

Thanks for writing.

There's no engine light or codes at all. Last year there was an engine light that appeared to relate to the catalytic converter, but a new sensor cured it.

The dealer seems stumped and isn't willing to take chances with new parts that the car might not need. I'm figuring ECU as well, but neither the garage nor the dealer want to do it without verification that it's what the car needs. The garage also suggested a bad ground somewhere, but that wouldn't explain the tach moving around on its own.

Regards,
Tom

[milanotom]

The dealer seems to think that there might be a ground issue (which they said would account for the tach having a mind of its own when the car wasn't running), but they'd need to start digging in the wire harnesses (beacoup time and $$$) to find it. Are there any electrical gurus who have a clue (based on the tach behavior) where to start digging, or is this something that would defy pinpointing?

Thanks in advance,
Tom