I am finally now working on my 87 Firebird formula with a stock lg4 with 79,000 miles. To make a long story short, the previous owner took off all the air pump stuff and seemed to remove and plug off all the evap system that would have been in front of the carb. All of the electronics on the carb, the new o2 censor and computer are still hoked up, but the electronics that hooked up to the evap system are unhooked. I just this last weekend put on dynomax headers, custom y-pipe, and hooker aero chamber cat back exhaust. It sounds awesome but caughs, spits, cokes and sputters going down the road. I just want to make sure what is supposed to be hooked up on the rebuilt quadrajet as far as what vacuum lines to hook up where, which ones to plug off before we do the final tuning on the car. If you could tell me what exact port on the carb gets whatever done to it I would greatly appreciate it. Thanks, Bret

 

There should be a vacuum diagram under the hood.

If not, check the FAQ forum for the vacuum diagram thread.

 

Try searching on scooter500 posts & look for the '87 LG4 vacuum diagram. Plus I am sure that I have posted ~6 pictures of my vacuum set up. If not let me know & I will post again.