I have searched the forums but have not found this problem.

Car starts and idles perfectly and drives fine.

The problem is at 1500-1800 rpm I have this slight surge. I have cleaned the throttle body and checked the IAC valve.
Anyone have any ideas - I am taking a long trip next week and would feel more comfortable if I could figure this out.
Car has 85K.

TIA for any help!
Larry

 

Did you check your tranny fluid and see if the color is red or close to it?

 

Thanks I will double check it today. Any other suggestions?

 

Try to disconnect the ECU fuse for a couple minutes, then reconnect it back in (refer to your owner's manual for the fuse location). This will allow the computer in your car to re-learn the driving pattern and may solve the surging problem. Just drive like you normally would afterwards.

 

I went ahead and changed the fluid. I also drained the differential fluid. Folks on the forum say to fill it back thru the automatic dipstick hole. I hope this is correct. My concern is on the transmission dip stick it says to check the differential by removing the plug. The amount of fluid taken to fill it was what I drained out of the 2 places. Could you confirm that to be correct to just fill it where you put in the automatic transmission fluid.

I did the ECU with no change.

Thanks for trying to help me.

 

For your 97 ES, if you drain the trans fluid and diff. fluid out( from the 2 drain plugs) you will need about 3 1/2 qts of ATF fluid to fill it back from the transmission dipstick tube.

Back on topic, your problem sound like the EGR ( Exhaust Gas Recirculate) valve malfunction. It's dumping too much exhaust gas back into the intake( to burn out some of the unburn fuel). I've seen some of the same problem on the ES and the little sensor on top of EGR valve fixed it. But, you still need to get proper diagnostic before start to replacing part...Good luck.

FYI, the EGR on the 97 ES is located right after the throttle body. They are two types of, one with the vacuum control and another one with electric sensor. I've seen the sensor goes bad all the time.

 

I have the service manual so it should tell me how to check it.

Thanks for the quick reply and info on the differential.

Will keep you posted.

 

I checked the sensor on top of the EGR it ohmed out ok. However the manual also gives instructions for checking it through the ecm. Will try that tomorrow.

 

I checked the EGR position sensor according to the manual and it checks ok. Any other ideas? By the way this is only when under load.


TIA
Larry

 

I occasionally get the same problem while cruising, the car will quickly surge back and forth, and the rpm needle fluctuates, it feels like taking foot of accelerator and pressing it back again, could it be a fuel problem, such as injectors, could using fuel injector cleaner do the job, if it is lack of fuel for a brief moment thru injector..

 

VVT-I above was correct. It was the EGR Valve position sensor. What I found is that it checked ok according the service manual- but you can unplug it and if that corrects the surging then just replace the sensor. Got mine from Plano Lexus in about 3 days. Takes about 5 minutes to change.

 

Thanks for the help guys!


Larry

 

Fixed the surge on my 98 ES300 by replacing the EGR and sensor.... Drove like that with the surge for about 9 months.. So happy now that its fixed.....

 

EGR Position Sensor was the fix. Chilton's said to OHM test sensor. The old tested no OHM and new one did as well. Replaced anyway and test drove. Awesome. I have been messing with Trans fluid level forever. It was a 32.00 part. Thumbs up Club Lexus.

 

I had problems with the EGR position sensor before.
At first, there was no CEL. A few weeks later, the CEL came on and pointed to the sensor.
I replaced the sensor. It was like a $30 part.