Hey everyone, long time member but haven’t been active in a minute. I need help and perhaps someone that either has had this issue can post what fixed it.
Got this 07 Gs350 with 198k miles a couple of months ago with some issues that I fixed and this one issue I’m hitting a wall with.
Cranks and turns on fine but will not rev past 3k rpm’s. Drives fine if I keep it under 3k and let it shift and I can do highway speed, if I step on it and revs to 3k it makes the needle jump and feels like I hit a limiter, shaking the engine a bit. If I’m parked and rev it at 3k I feel like the transmission torque converter shakes, like it’s unbalanced.
Things I checked and changed:
Changed the crank sensor, checked wiring, traced it to Ecm and both red and green wires are fine and have continuity.
Checked and cleaned the Maf, I tried 2 different ones, same outcome.
Checked transmission, disconnected the torque converter from flywheel, same issue persists.
Changed the upper Catalytic/ manifold on both sides to pass smog (California) it passed.
Checked the reluctor and all 34 teeth are there, 2 look a bit bent but it starts fine and rpm are consistent on the tach and scanner.
Spark plugs changed and same coils as they work fine unplugging them while engine running.
I got a p894 code transmission component slipping code but hasn’t come back after clearing it, I thought transmission would be the problem but after disconnecting it from engine, no cigar.
All I got left is getting another Ecm but before dumping more cash and not being able to check mine for issues I want to get ideas and opinions and perhaps a fix from you guys.
Thanks.

 

Hi Smooth, looks like you've done a lot of preliminary checks but noticed you did a visual on the reluctor and mention 2 teeth look bent.
If you want to see if the bent teeth are causing a problem when operating over 3K RPM's you can see the quality of the signals on a scope.
For an afordable DIY automotive scope I use the Hantek(ebay) and has enough channels to scope many things simultaneously at the Engine Ecm

Did a review on it here for anyone needing to scope out complicated diagnostics: https://www.clublexus.com/forums/rx-...agnostics.html

Wishing you success on your fix!

 

You need to take it to a good mechanic that will run a scanner/scope and monitor the sensors. I know you dont want to hear this. But, all you are doing is throwing parts at it in hopes of fixing it. What you are doing you may bring more problems by removing and checking stuff. Also the sensor that you replaced was it oem/denso or did you run an aftermarket?

A good tech with a scanner will allow them to see what the sensors are registering, it could be something small. But look for a specialist in diagnostic and pay for 1 hours worth of labor.