BradTank

My 04 LS430 stalled out on me.

It's been a while since I've had a car simply break down and had to get a tow truck.

Car drove fine, I came to a stop, pressed the accelerator pedal and she stalled out. I tried to restart, it cranked over fine, would maybe idle a half second then stall out again. I would wait, try it again a few minutes later, basically the same thing. Battery is relatively new, and no problems turning over. No codes have ever been thrown.

The car had been left alone for a few hours, went out and it started up just fine.

I'm going to clean the throttle body and MAF sensor this weekend. Any other areas to look at? I hate "shotgunning" parts at a car, but I may throw on a new TPS sensor on it since it's only about what I pay for a tank of gas.

I would think if it was ignition related, it would throw some codes. My fear is it needs a new fuel pump.

I hate coming into a dealership with an issue like, they're going to want to just start throwing expensive parts at it.

Any advice would be appreciated.

sikIS300

The tps is fine. Tps will throw codes. Try cleaning your maf and throttle body. Disconnect the battery for 5 min to reset the idle. Ive never heard of a bad tps or fuel on a ls430. Also ck and see if its not overheating cus it will shutoff if the car overheats. Btw im a lexus tech just to let u know. Let me know how it goes.

toyo

If the car won't start how is he to know if the check engine light is on? You will have to get it scanned to see if there is a code. Sounds to me like you might have a fuel related issue. Check the fuel pump relay 1st.

Lynzoid

Tell me please, does you 'tree' lights up when you turn ign on? Tree = the PRND indicator on dash.

tofu

If your car runs fine but stalls at stops more than likely the idle throttle need to be cleaned, the best way is remove the hose came from air filter box connected to the idle throttle body, spray a bunch of carburator cleaner on a clean rag then flip the flap, reach in as far as you can, repeat cleaning and that should fix the problem.

BradTank

Thanks for the response.

The reason I was looking at the TPS being an issue is I had a car before with a similar issue where it needed to be replaced, it was almost like the fuel just being cut off.

BTW, in your response you said you've never heard of a "bad fuel" did you mean "bad fuel pump"? If so, that's a relief.

Car wasn't overheating, temp gauge was where it always is.
I'm going to start with cleaning the Throttle body and mass air.

The only other issue that may be related is I sometimes get the sulphur smell from my exhaust, but it sounds like that's a pretty common issue with this generation LS.

The car started up fine and I was able to put it in my garage. No error codes came up.

Thanks again.

BradTank

Cleaned out the Mass Air and the throttle body and unplugged the battery overnight. So far so good, it seems to idle and drive a lot smoother, but that could just be in my head. It hasn't stalled out since.

The Mass Air sensor looked like it had been dipped in black paint before I cleaned it. The throttle body was also dirty as well, but I'm betting the mass air was the main culprit.

I'd definitely recommend doing this service, even if you're not having issues. Don't wait until it leaves you stranded, it's very easy for the DIY'er to tackle, not much more difficult than changing an air filter.

BradTank

Update #3

Looks like I spoke too soon, the car is doing the same thing. Any ideas?