Trying to figure out what it is that could go into that hole there in the intake on the driver side of the engine where the plenum connects to the intake at the bottom

 

Cold start injector is missing...not necessarily a bad thing as long as you get the block off kit and get a new chip with the 89' start up code. Also make sure the fuel rail end of the cold start injector is plugged too. If you want a CSI I have one from my car that was in working condition when removed last year. What year is your car?

 

it’s an 85 z28 engine that I’m putting into my 91 RS

 

I would just block it off then and get a chip burned with 89' cold start up. Are you running the ECM from the 85?

 

yes I am how do you get a burned chip

 

https://tunedperformance.org/ and he is a member here with the handle Tuned Performance.

He can likely set you up with a PROM chip. I have a basic chip he set up with lower fan temp activation, 89' cold start up, VATS delete etc. that really helped my car perform better and run cooler.

Ebay also has a few of those 9th injector block off kits too for under $20.

 

yeah I already ordered one of them thank you so much for all the help

 

Glad to help, good luck with your swap.