Festyk

Hi guys.
I have strange problem with my Lex. I bought it like that so I don't know when this thing started but it's odd.
Most of the time when I gently let off gas, car is doing strange hit sound and also shake.
But in speed range between 70-90 km/h letting off gas causes jerking back and forth until I add more gas or let my foot off the pedal. It sounds like the engine is choking but I have no idea why?
For that moment I replaced:
- sparks and wires
- o2 sensors
- cooling temperature sensor
- cleaned throttle body
Next items I think could be the problem are:
- coils
- maf sensor
Of course I don't want to just replace half of the car with hope that something will finally solve my issues.
My suspection is that my car is calculating too rich mixture and after letting my foot of, it's choking because of unburned fuel. Could someone tell if that makes sense? It the answer is "yes", where I should look for a solution?
I have no error codes stored in my computer.
Thanks for all suggestions. I love my car but now I am so dissapointed and depressed that I am starting to think that I will never find an answer for that

RA40

iTrader: (6)

Year and how many miles/km on car? Any error codes? Until you get some error codes I wouldn't suggest a parts hunt.



May read through this:
https://www.clublexus.com/forums/ls-...capacitor.html

A possibility:
https://www.clublexus.com/forums/ls-...hifting-6.html

Festyk

1995 with 329000 kilometers. There is no error codes and I also tried second ECU for a while - no differences. I think that something is sending wrong readings to ECU but have no idea what? Is there any diagnostic procedures of MAF in UCF20?

Festyk

No ideas? Anyone? Please...

sndlight

Transmission mount is the usual suspect.

Festyk

Transmission mount would force engine to choke? I doubt it.

dicer

If its and obd2 the good news is a nice fancy scan tool can be used, to try to trouble shoot it.
Cut out? Could be a bad spot on the tps resister. Ignition like coil and timing sensors would be in all speed ranges. And Maf possibly, need a scan tool to take the guess work out. A good one will run $1000. up so maybe have someone check it. Not with a code reader.

plexus914

Check propeller shaft joint / flex joint.

m0ist

This. Sounds exactly like the symptoms when one of these goes bad. It's also called a guibo.

Legender

cheaper than a scan tool is the bluetooth OBDII port adapter and the Apps for the Iphone or Android. This will let you read the sensors realtime and determine if you do have a mixture problem. Very strange that you don't have some type of code with this severe a problem.
You say it sounds like engine choking, but can you isolate it to either the transmission or the engine. Sounds more like a drive train issue to me.

dicer

He says when "gently" letting off the gas. That should not even affect a bad engine or trans mount. Its rapid gas pedal that causes that stuff. And the mount issue would be noticeable all the time.