Hi i just swapped an ls1 in a 72 nova and almost finished but having a few issues. I want to block all the vacuum ports on the intake so i blocked the Hvac one but when i block the brake booster port the engine dies.. It runs great when left open just idles high and make the horrible sucking noise..
please if anyone knows what to do let me know.

Thanks

 

IAC not working?
NE scan logs?

 

If you plug the booster line up can you restart it? I wonder if the computer has completely closed the IAC off because of the leak.

I wonder if you could get it started, might have to hold the throttle open a little, let it warm up and have the computer relearn the idle.

 

idle air trims move slowly; may think about unhooking the battery before re-trying with the booster hooked back up.