I have a 2001 Lexus RX300. The issue I’m experiencing is lunging, or surging, or a feeling that the car wants to die while driving. After I’ve driven for roughly 10-20 minutes, and the car has warmed up completely the issue starts. When I’m stopped and then start to go it lunges as if it isn’t getting what it needs to go. It does that the whole time, but gets a little less noticeable the faster I go. Once I’ve driven for several minutes and come to a stop at a light, stop sign, etc., and start to accelerate it continues to give the lunging feeling the whole time. It’s especially noticeable when I’m trying to keep an even speed. It does this until I hit about 60-70mph.
If I accelerate hard it isn’t nearly as noticeable, although still there.

This was an issue we had for a couple years, but went away after a fuel leak was repaired last July.

It started back up about a month ago, a week after getting my radiator replaced. My mechanic hasn’t been able to figure out the root of the issue at all.

Only thing that makes sense to me is there is a gap or hole somewhere or in something that’s causing something to not get where it needs to be. I say that because it only happens once the car has been driven for a few minutes and all the parts have warmed up. I’ve also noticed it’s a lot worse on days where it’s warmer outside, and when my gas tank is low.

I keep hearing great things about you and hope you can help solve this mystery. Thanks for your time!

Comments
No. 1-1
ScottyKilmer
ScottyKilmer

Editor

Well, have the fuel injectors pressure cleaned and also have the MAF sensor tested, weak ones can do just that. And also pressure test the fuel pump