Hi. My g35 was slipping. She got a new transmission. Solid mechanic did the work. Now she drives ok but at 20mph if I try to accelerate it hardly responds. Like 2-3 seconds to respond. If I’m at 50mph and hit the gas it responds in 1 second. What could do this ? I unplugged the battery for 2 hours. No change.

 

I had the issue that the gas gauge needle would circle around when battery jumped or changed. New transmission- gas gauge works - unhooking/ rehooking battery did not effect it.

 

What transmission did you put into your G? Was it from a VQ35HR engine like a 350Z or 2007-2009 G35?
They're very specific for the VQ35HR engine and the valve bodies are also very much different. You should of swapped out the TCM from the old one to the new one (transmission controller).
You would need to use a scan tool and clear the adaptive transmission data (reset the trnas computer) and drive it for 15-20 miles without abuse so the computers can learn.