Hi everyone, I recently purchased a 1987 300ZX non turbo that has been sitting for 11 years. Taking it out on test drives I’ve noticed an issue. A few times I’m driving around and the car would kinda run rough, then I’d reach about 2500 RPM and all of a sudden it would stop running rough and would accelerate nicely. Car idles great and when revving it seems to also be smooth. It’s only sometimes while driving it. Seems to happen around 1500-2500 RPM and then would clear up. Is there maybe a valve of sorts that’s sticking? Could this be an issue with the throttle body position sensor? CHTS is brand new and so is the harness so that’s out of question. Fuel pump and filter also only have 20 miles on them. I have fixed a few vacuum leaks but will likely look for more later as it may be a vacuum issue. Thanks for any tips!!