Hi,

I have a 1998 Lexus ES300 with about 200k on it. Overall it runs great!

Car starts cold perfectly every time. But if I were to run an errand and then try to start the car it may not start or it starts but seems to be barely running then it might die. I can rev it up ok but it may still die. If I were to try and put it in gear and try to drive while it's doing this it would die. But after a couple of starts it will run and idle just fine. But after my next errand it may happen again.

This issue happened multiple times today as I was running errands. After I got home my car sat for about three hours and started right up. It was probably still a bit warm as it's 70's+ today.

Is this a fuel pump or fuel pump relay issue, or?

I have been running mid grade fuel lately instead of premium if that makes a difference? The issue also seems
to be worse now that it's warmer outside. But...

Any insights are appreciated!!!

Thank you!

This usually points to the idle air control valve meaning it needs to be cleaned.

Conceptually, what happens is when it's warmer - car hot or warmer weather - the gap between worn electrical components/junctions opens up.

On other cars, you can often take a good guess and say, "hey that's likely the crank position sensor" or the "cam sensor 99%."

On the pre-DBW 1mz-fe, classis is the IACV as L2k said. You can google that and see how to clean it. Take off the intake and it's below the throttle butterflies. Many how-too's out there. Fuel grade is not an issue here.

+1 on the IACV. I had the exact same symptoms when I bought the car with 173k miles. Search YouTube on how to clean it.

1994 with 240k and have been experiencing this exact behavior starting last year. I even settled on the "hey that's likely the crank position sensor" and replaced it despite passing a voltmeter test. It seemed to fix the issue, then the weather warmed up and the issue has returned. IACV cleaning is now next on my list. Thanks all.