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Intermittent smoking and sputtering

I have a 93 lexus sedan… It runs fine most of the time but will start running real rough and clouds of white smoke will come out of the exhaust plus the smell of gas purmiates the interior. Generally it will run fine the next time i start it… Any clues ? Since it is intermiten it is hard to figure out… I have a 3yr old and i am frightened to use the car lately…

It just sounds like you’re going to need to have someone look at it.

The rough running + clouds of white smoke suggests a bad head gasket.

The rough running + smell of fuel + clouds of smoke suggests an overly rich condition perhaps created by a faulty fuel pressure regulator or other kind of fuel delivery problem. In this case, however, the smoke should be dark - gray to black.

Of course the smell of fuel alone is a good reason to just have someone look at it right away.

Any chance the episodes correlate with fill ups?

seems to be random…

Similar problem - '98 Lexus runs just fine most of the time, but will occasionally run very rich. No check engine light comes on. Had it at a mechanic and he had no idea - Said it probably needs to get worse before he can figure out what is wrong. After shut down and resting for a couple of hours, it runs fine again.

Have someone check for a leaking fuel pressure regulator.

The white smoke is probably from vaporized gasoline that wasn’t burned coming in contact with hot exhaust components.