Drivabilty issue.

[BBBAD94ZR1]

I hope you guys can help me out. I got my Z home today a 94 zr1 10k miles. The owner washed off the engine with a hose a big no .
I blew it off and the air cleaner had some water in it. No much. Here is the issue. I drove car for around a half hour mellow, I got on it a few times not going past 4500 rpm and I noticed a stumble. Drove it a bit more and I noticed if I shifted form 3rd to 4th at low rpms the car hesitated kind of like it was missing or starving for fuel got on it and it did not happen for a while. I let the car sit for a few hours took it back out and it ran better however when driving in 5th around 50 to sixty under accel the car stumbled. Go to 6th and it really ran bad drive it hard and its ok when in to high gears under light accel it stumbles sometimes? .
The car also had the chip changed here is the number of the one not in the car GM#16209008, the one in the car is 12528772 gr.3.670. Anyone know what the difference is between these two?
Please give me your input. Anyone know of a gm dealer in Nj who has a Zr1 tech? I hope its something easy to remedy.

Thank you
Ray