Surging during acceleration

FOURPAWS2

MEMBER
2002 LEXUS ES
41,000 MILES

Under WOT the pulsing does not occur during acceleration.
I have cleaned the MAF with CRC MAF cleaner, no change.
I have replaced all vacuum lines, no change. I have used carburetor cleaner to identify additional leaks with negative results.

There are no DTC's from the engine or transmission

The Lexus dealer tested the vehicle for six hours stated "it is probably the transmission for $4,200.00. If that does fix it its probably the TCM for $900.00". The transmission fluid was dirty and was changed along with a flush.

They say it "probably" it needs a new transmission, yet when in park and in neutral, the rpm pulsing occurs between 1,800 and 3,000 rpm's. That is if you hold it at 2,000 rpm's, the rpm's oscillate about 2,000 rpm. When driving the car surging is very obvious and noticeable and potentially dangerous.

It does not stumble or shudder.

The pulsing is smooth and is a decrease in rpms as if smoothly cutting out. The pulsing has progressively become worse within the past few months, over 200 miles.

The vehicle has 41,000 miles.

Again the rpm's do pulsate between 1,800 and 3,000 rpm's when the vehicle is in park and and in neutral, which makes me suspect fuel delivery or pressure issues.

the vehicle shifts without a problem. The transmission is fully engaged engaged when the pulsing accelerations occurred. It is not evident when driving at fixed speeds.

You assistance is greatly appreciated.

5 Replies

FIXITMR

MECHANIC
9,990 POSTS

If fuel issue what about filter?

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Tuesday, January 17th, 2012 AT 7:53 PM

FIXITMR

MECHANIC
9,990 POSTS

Being in tank is a bummer. At least you can access under rear seat.

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Tuesday, January 17th, 2012 AT 8:00 PM

FIXITMR

MECHANIC
9,990 POSTS

This car should be the first year for drive by wire which makes me tend to suspect that it has something to do with it. Your issue is so common there should be a recall! Did you check throttle plate for crud? If it is, do not jump to cleaning it until you do research on how to do it safely.

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Tuesday, January 17th, 2012 AT 8:14 PM

FOURPAWS2

MEMBER
2 POSTS

After replacing the fuel filter and the fuel strainer in the tank, which was very easy and inexpensive. There was no change and the car continued to surge.

I also took my fuel injectors to RC engineering located at 20807 Higgins Court
Torrance, CA 90501. They found two injectors that were severely plugged and were only dripping. The rebuilt the fuel injectors were placed back in the vehicle but the vehicle continued to surge.

I subsequently took my car to Ron at The Transmission Man located at 24309 Creekside Road in Santa Clarita. I have trusted him with all my vehicles and has always been great at explaining the necessary work and has always done quality, necessary repairs on my vehicles.
After dropping off my car, after a couple of hours, the technician at the Transmission Man determined that it was a bad oxygen sensor that was causing the surging. It was not the transmission. Apparently the O2 sensor was oscillating between lean and rich readings causing the PCM to respond and compensate by either cutting off or injecting more fuel into the cylinders. The scary part is this situation never generated any DTC codes. The PCM read this behavior as normal. And again, after Lexus of Valencia, the dealer had my car for over six hours, they could not figure the problem.
Keep in mind Lexus of Valencia wanted $4,500.00 (after looking at the original written estimate, not $4200.00) plus tax for a rebuilt transmission and $900.00 plus tax for a TCM. Yes $5,400.00 plus tax for unnecessary transmission work that would not have repaired the problem.
The transmission Man repairs were $488.00 out the door and it was fixed.
Lexus of Valencia would not have refunded $5400.00 plus tax even after the transmission and TCM replacement failed to correct the problem. This being said, there is no doubt the repairs probably would have climbed beyond $7,000.00 at Lexus of Valencia.
So as a shade tree mechanic, trust your instincts, the dealer is not the best place for repairs and get several opinions. You will not be disappointed.

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Thursday, February 23rd, 2012 AT 3:35 PM

CHASGHALL

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1 POST

I know this is an older post, but it was the key to solving a similar issue with my 2005 ES330. With 168,000 miles, I thought the surging might be fuel filter, fuel injectors or spark plugs. After rebuilding the fuel pump (while changing the filter), new plugs, and refurbished fuel injectors, still surging during early acceleration (2,000 to 3,000 rpm's). My OBD2 reader is not sophisticated enough to diagnose O2 sensor oscillation, so I decided to spend another $300.00 and replace all (four) of the O2 sensors (Denso OEM), and it runs great now. Thanks for your post!