TEXAS83

This just started happening in the last week. I turn the car on, and 2 seconds later it turns back off. I have to remove the key, stick it back in, and turn it on again, and it dies again. I have to do this 2-3 times before it turns on and stays on.

I know I'm due for a tune up - could this be the problem? I don't know anything about engines. Please help! Let me know what the tenative problems are so I don't get hosed at the mechanics. Thanks!

VVTiBob

Well there could be a slew of thing wrong, one that pops up is the engine immobilizer system, not getting a signal from the key. Have you tired using another key? Are there any other symptoms?

TEXAS83

No other symptoms. The car does turn on - it just immediately turns back off after 1-2 seconds. After repeating the process 2-3 times, the car turns on and stays on. Its the only key I have, been using it for 4 years without a problem. Any other ideas?

Poqman

Sorry to hear you're having problems. I had a key break in half while out shopping. Not wanting to call the wife to bring the spare, I held the transponder next to the key while turning it to start. The car remained running after I put the transponder in the console. So I would guess the transponder is only needed to get the car running, but not required to keep it running. As a guess, it could be a timing sensor going bad.

scdroptop

iTrader: (1)

Texas-key issue is what initially popped in my mind too. Try a new battery for it or another key-easy, inexpensive fix if it works. From there I'd start looking at the battery terminals and the charging system in general--maybe even starter solenoid. Fuel pump and Mass air flow sensor could be other suggestions.

Any idling issues at all?

Habious

I can say with confidence that it's almost for-sure NOT a key (immobilizer) problem.

I've had a key/immobilizer problem...the symptoms don't match.

If the key is not working properly, the car won't start. Period. It'll just crank and crank.

Also, Poqman is correct; once the engine fires up, the transponder is no longer necessary to keep the engine running.

I'm wondering if it's some self-diagnostic thing that's failing and shutting the engine down.

Of course, it could be something as simple as a dirty fuel filter.

cjs18

Shouldn't the security indicator LED go off if the immobilizer is satisfied that the key has the correct code?

scdroptop

iTrader: (1)

Earlier SC's, ES's and LX470's had problems with fuel filter stalling. I read some posts on that on several sites. Nothing on the SC430 though.

TEXAS83

First off, thanks for all the replies. One thing I forgot to mention is that it does NOT happen every time. For example, I had the problem occur on Sunday and Monday at least 5/6 times, whereas yesterday and today have had no problems at all, the car started fine like normal.

ScDropTop - you asked about idling. Once the car is on (and staying on), it has no problems at all. No funny sounds, no problems accelerating, nothing.

So suggestions I am going to go with:
1. Dirty fuel filter
2. Fuel pump and Mass air flow sensor
3. Starter solenoid

Anything else to chime in before I take it to a mechanic?

Habious

I'm NOT a mechanic but, it doesn't seem like...based on the symptoms you described...that it shouldn't be any of those.

If it were a fuel, fuel pump, or MAF issue...I would think that the car would have difficulty starting, run rough, have problems idling smoothly, and would intermittently stall while on the road - like when you stopped at a light(not just within 2-3 seconds of start-up).

If it were the starter solenoid (or starter), you'd have problems getting the car to crank/start. From what you describe, it cranks and starts fine...just won't STAY running, correct?

I still think the computer is shutting the car down for some reason - detecting something it doesn't like.

TEXAS83

I should have mentioned that I have had a weird starter for over 2 years. I got the timing belt changed 2 years ago and started having this issue where you would have to crank (turn the key in the ignition) for about 3/4 seconds before the car would turn on. I took it to Lexus dealership when it was still under warranty, they ran all sorts of tests, and said everything was fine. The car ALWAYS turned on, no matter what, and they said that the 3/4 seconds was within the prescribed time frame for it to ignite.

But this business with the car turning on, then turning off instantly, that's all new. I have a Luxlink installed, but have had that for over 3 years with no issues, and no other modifications.

Habious

Just as a quick warning...

When I started having my key/starting issues, I took it to the dealer, under warranty. They took one look under the dash, saw the LuxLink and all of it's wiring, and told me "Sorry, we're not going to touch this until all of THAT is removed."

JohnnyCake (here on the forums) also had an issue once with his steering wheel controls (turned out to be a bad spiral cable). The dealership blamed it on the LuxLink (which it wasn't) and actually ended up smoking his LuxLink trying to remove it...and you can't buy a new LuxLink any more!

TEXAS83

Thanks for the warning. I don't plan on taking it to the dealership to get looked at. I have a local Toyota guy I use in North Dallas who's worked on all my cars. I just wanted to give him a list of suggestions from ya'll so he might have somewhere to start. Its difficult to replicate the problem, hopefully it just starts working right!

Habious

Yeah, intermittent problems are the worst to troubleshoot.

cjs18

I think your Toyota technician would want to see what DTCs are registered when the engine stops. The computer should be storing some code that would give some clues. Good luck & hope it's a straightforward low-cost fix.