Engine starts and goes dead immediately, will restart and runs perfect

HAROLD MEDDERS

MEMBER
2006 LEXUS LS 430
4.3L
V8
2WD
AUTOMATIC
50,000 MILES

This problem is not consistent, normally occurs first start in the morning after overnight in the garage. Had throttle body and plate cleaned, still have same problem. Car has been pampered and has very low miles. Original owner only drove during winter months in Florida as his snow bird get away was in Miami. I purchased the car appx. 14 months ago and just now started having this problem.

1 Reply

CARADIODOC

MECHANIC
33,873 POSTS

The most common cause of stalling right after starting is fuel pressure that has bled down. That is typically caused by a leaking injector. The fuel that leaks into the intake manifold will sit there and that's what the engine initially runs on, but it stalls before the pump has time to build the pressure back up.

The pressure can also leak down through the fuel pump's check valve or the fuel pressure regulator. Those will cause a long crank time before the engine starts. None of those conditions are serious. To verify if low fuel pressure is the cause, turn the ignition switch to "run" but don't crank the engine. Wait a couple of seconds, turn it back off, turn it back to "run", wait a second or two, then crank the engine. The fuel pump will run for about one second each time you turn on the ignition switch. That will give it extra time to build pressure.