Posted on another forum but nobody seems to be on so trying here. Please let me know if off topic. Hoping somebody has seen this before and knows what to look for


"Hello,

As mentioned in title, '05 LS430 with ~73k miles in pretty good contition.

Issue: Started Saturday morning, driving for like 5 minutes on an almost full tank, went to turn left at a light, engine cut out, dash lights turned off, radio stayed on. Coasted into a parking lot, and was able to start the car again. Drove over 60 miles over the weekend and it happened like 4 more times, all while doing a turn from a stop or a slow coast, sometimes the dashlights went out and sometimes they did not. I'm posting now because driving today it stalled turning into a gas station, turning out of it, and even when gently merging into a lane, all within 5 minutes], so it's gettng scary persistent.

Things I've tried:

Only explored intake so far, Changed air filter, Cleaned MAF sensor, checked throttle body which looked clean. Thought that worked till it went to hell today.

If I need to add more information please let me know, I work in IT and users like to give me useless information overload when describing an issue, so I'm trying to not be that guy. Any help would be appreciated!"

 

It sounds electrical. Have the battery and alternator tested. Take a look at your grounding to the body if those test out. No codes?

 

Thank you for responding, I thought the same thing as well but forgot to mention it. Here are additional details:

Just gave it a look, connections are snug and zero signs of corrosion. Some details I forgot to add that may be relevant:

Check engine light not on, no codes that I know of and Advanced auto refuses to do OBD scan if no check engine light. At night when it died like 4 times in a two mile stretch, even though the dash lights went out the headlights and radio were fine.

Also, this has happened both when the AC is off and when it is OFF, if that matters at all

I used to have a 78 Volare that lost an alternator and a battery, so as far as those issues I am used to the symptoms and it doesn't match up with what is happening here. When my battery, alternator went bad in my other car it wouldn't start again at all without being jumped, this starts no problem after stalling. I do wonder of the connection with low speed turning and stalling, since that seems to be the only consistent way to cause it, alhough it only increased in frequency tonight on the way home from work. Thank you again for helping me with the diagnosis

 

i think the float for your fuel pump is messed up...especially since it only happens when your turning.

 

I was thinking of looking at the fuel pump next but wasn't sure if it was more electrical or not. I am not a mechanic or even that savvy by any means, however when troubleshooting my thought process was this:

Since it seemed to be choking up at low RPM while turning, I figured maybe something with the fuel/air mix was causing it to die. So I started with intake, being air filter, MAF, throttle body, etc to make sure it could breathe properly. Assuming that didn't help, which it didn't, I was thinking about looking at the fuel system next. The fuel filter is in the tank, so that blows, however outside of that I figured I could try sea foam and afterwords take a look at the fuel pump. Not being a mechanic, however, I had to assume that I was taking the wrong approach in diagnostics lol

Would the fuel pump thing go from mildy intermittent to almost killing me on the way home? I'm not to sure what to look for

 

One possibility is that the battery cable has a corroded connection close to the battery end, where the clamp attaches to the cable. This is a fairly common problem, and can't be seen unless you are looking for it.
I would guess that it is indeed electrical, since your dash lights go off. I am not aware of any common fuse or wiring, but I could be wrong.

 

I checked for corrosion and didn't find any, it was almost beautiful

I thought electrical too but since the headlights/radio still work when it stalls and the dash light thing is random, I figured if it is electrical than it is probably going to suck since it's not as basic as batter/alternator going bad. The other thing that makes it seem electrical in nature is the fact that it doesn't sputter and die it just goes from turning to a smooth, Lexus death >.>

The fact that it has gone from like twice a day to four times in a few miles is what is scaring me at this point

 

Start with the most obvious. Battery and alternator. You need to have them tested.

 

well for it to happen only while turning, only means that the fuel slosh is starving the fuel pump hence cutting out the power. maybe it got clogged somehow?

 

Same effect with full tank? I'm running seafoam through it tommorw based on reccomendation, just kind of hoping I get to work alive at this point. I am walking distance from advanced auto parts, so hopefully somebody has ideas if it stalls as bad tommorow morning.

 

It certainly could be fuel related but would first check any possible electrical connection related - I'd start by disconnecting, inspecting and reconnecting battery cables and ground straps, connections to alternator, etc. Some wild guessing - motor mounts causing excessive engine movement may contribute to bad behavior on connectors and hoses getting pinched.

 

Lots of reported issues of the car stalling when the gas indicator is at 1/8 tank but first I've heard of with a nearly full tank.

Since you say it's only happening on turns why don't you put the car in park in your driveway and start turning the wheel and see if that stalls it out. If so might be something in your PS system. If that doesn't stall out, start doing some 360 turns in a parking lot. If turning the wheel doesn't stall it out then you can eliminate "turning" as a symptom. Rather consider what happens to the fuel and electrical system while turning that may be causing this. My gut feeling is this is a fuel-delivery issue.

 

Well guys, thank you for all the help so far.

As it turns out, in my troubleshooting process I assumed the battery wouldn't be the culprit since the car started fine and lights/radio worked when stalled. After re creating the issue this morning by staying in park and turning the wheel around, I was scared to drive to work so I limped into an advanced auto. Sure enough, the battery was bad, with apparently enough charge to start and keep the car going but not enough to handle the electric assisted steering. So yeah I feel dumb, and I've learned a lesson about assumptions. Thank you guys for the advice, I learned alot about my car in the process

 

Thanks for sharing the info/detail on the possible resolution. Hopefully you are good to go at this point.