need help with vaccum lines on 89, the two lines under the rear of the plennum, and the two lines under the front of plennum, that is bolted to thermostat housing, replaced gaskets, and as you guessed it, dont know where they go ......thanks

 

With a vette of that vintage, I suggest you invest in a set of shop manuals. This is the set sold by General Motors and some of the vette after market suppliers, Ecklers, Corvette Central, etc. They are a little on the expensive side but worth it in the long run. They have wiring diagrams, vacuum line diagrams, testing procedures +. There are also some online dignostic services. They require membership.
Skips

 

Please stand by.........

I'll run out to the shop and take a look at mine. As soon as I can. Mght be a day or two but I'll get it for you. You know how it is, not enough hours in a day or days in a week.

 

Hey, I took a quick look, OK there is a larger one and a smaller one that come from the area under the left headlihgt. (i didn't check where they went I think one to the evap. canister, and the other to the vacume ball) the larger of the two goes to the pass. side of throttle body. the smaller one splits in to two, One of those goes to a port under the plenum and the other goes to the "rubber thing" by the thermostate housing. The other one from the "rubber thing" goes to the EGR valve. For the back of the plenum, on the pass. side there are two ports.One forward one goes to the fuel regulater, the other crosses over to a valve that then splits.

SkipS has a good suggestion on getting manuals, however I do have the Red GM shop manuals for the 88 Vette and believe it or not, the vacume routing is not shown. Go figure.

I hope this helps you out. Once you get some connected it should be a process of elimination.

Good luck and please let me know if you get er figured out.

joe