My 1998 LS 400 engine stopped when my wife made slow, sharp turn. It happened 4 times today, but can restart quickly. What's the problem? I noticed that when cold started and idling, engine does not run as smooth as before, but not too rough, just I can tell that speed up and down a little more than before. I know the car battery was dead 3 times in past 3 month, because I parked it in company lot and car pooled with wife. These days she is driving it regularly, with short commute of 10 miles one way. Somehow 2 days ago, it lost battery in the morning for no reasons. I jump started it and no problem. The battery is 2 years old, but only with less than 10K miles on it. The car is 188K now. No other problems. I can almost say, it runs like new. Hope someone can help me diagnose before I send it to my mechanics. Thanks!
This not being a Lexus forum although related via Toyota is not making it easy. The first thing I would check is the engine oil level as there could be an engine inhibit for low oil pressure and when taking sharp turns with low oil could cause your problem. John (Britprius)
1) Replace the 12V battery again, since you know that is a problem. Fully charge the replacement before installation. If the car is going to continue being driven at such a low rate (5K miles per year) then periodically charge the 12V battery overnight, once per month. 2) Check fuel line pressure both at engine idle speed and when the engine is revved up to max RPM. A flaky fuel pump that is not providing adequate pressure might be causing the engine stop problem. How much fuel is in the tank when this problem occurs? Does it matter if the fuel tank is full? 3) If the fuel line pressure meets spec then replace the spark plugs. Check the engine air filter and replace if needed.
The battery is tendered bi-weekly, in good condition. Yes I had a code, fuel pump related, 6 month ago when engine light was on. But somehow its off later without anything done. I believe that's the cause. Will check it out and replace pump if need to. Gas was half full at least. Spark plug only 60K miles on it. But it should be easy to check. Thanks Patrick! You are always spot on and very helpful!
It's cheap insurance to replace the fuel filter whilst replacing the pump... even cheaper to just do the filter first and see if things improve.
It looks like low gas level is the cause. And it makes sense. I filled whole tank gas, the problem goes away. Thanks for all the help, especially Patrick. Case closed!