Curious if anyone has experienced this. At between half to wot acceleration the tach drops off, however the engine is clearly spinning at 5k+. Scanned and throwing no codes. Searched and could only find some old LS 400s that had a leaky ECU capacitors. Probably of no connection, but I changed water pump, spark plugs, and serpentine belt. I couldn't find the crank position sensor(s) in a diagram to check if those may be loose or somthing. Thanks in advance for the help

 

If the crank position sensor had an issue, you'd have DTCs for sure. It's at the core of how the ECM works.

I've never heard of anyone on this forum having an issue like this. Very weird.

 

Battery or hopefully a minor electrical issue. I had the gas gauge go bonkers from a cheap LED light I had installed in the overhead dome light. I found it because the door was open longer than usual when I began troubleshooting, which in turn had the light on longer, & could smell it start to burn.

 

When it comes to strange electrical issues, always a good idea to test the battery first

 

Also the alternator...!!

Autozone can run a free battery load, starter & alternator test..

Although I typically wouldn't recommend it, if you find a trust worthy person there, they have their handheld that can test these primary components..

Joe Z

 

I had all gauges, radio, etc go out intermediately, but that was b/c a tech left my negative terminal loose on the battery. Hope that helps

 

Thanks for the help guys. I'll start with the battery and get the alternator tested too. Fingers crossed!

 

Wow, going on the LED light trail I disconnected a new bluetooth dongle with inline interference reducer and just went for a spin. THAT WAS THE CULPRIT! Thanks a million, exactly why I love this forum.