Hello, I've looked and looked, and to no avail.
I am having a serious issue with my 1993 240sx vert(automatic), ka24de stock engine, recently picked it up, 126,000 miles. Very nice pickup, especially here in 2023.
Nonetheless, the issue I have been having has gotten worse as it was driven.
When I start up the car, let it warm up, then go and test drive it, the first rev-up is clean and it revs all the way out. The next time, the car refuses to shift gears, it bogs 4k rpm, 3k rpm, and sometimes lower depending on the speed. You can't gas it if it's been 20 mins of driving, you can only give it 20% gas. It's like it's in limp mode, but I feel if that was the case, it'd stick to just under 3k rpm and not fluctuate. This problem is sometimes inconsistent also...once I was done test driving and decided the issue wasn't fixed, my buddy fiddled with a few things under the hood(pushed some fuses in, moved a few grounds around), went to drive the vehicle and it was perfect until I slowed down to turn around.
Parts I have already addressed:
Spark Plug Wires
Coolant Temp Sensor
Ground connected to head, attached to rear fire-wall
Fuel Filter(prev owner)
Fuel Pump(prev owner)
I will say the coolant seems full and completely bled, with no air bubbles.
Any help would be appreciated!