Checkerbelly

Hi guys. I just found this site. I just bought an 85 z28 with a carbureted 305 V8 and 5-speed manual . I'm trying to figure out what the heck the original owner did to this car. Best I can tell, he tore out the CCC quadrajet and stuck in a mechanical one. The distributor is a vacuum advance, so I suspect he swapped that too. My best guess is that he took vacuum lines and stuck them in random places until it looked good and ran OK. It doesn't match a CCC carb vacuum diagram OR a mechanical carb vacuum diagram.

What I can't figure out is what distributor was original to the car, and where vacuum lines are SUPPOSED to be plugged in. Right now the vacuum distributor is plugged into a nozzle on the passenger side of the carb. I don't know exactly what quadrajet carb is there now, or if this is the right spot for the distributor vacuum. Is there any kind of diagram that shows a quadrajet and says "this vacuum nozzle connects to this, and does this..etc"?

Any info you guys have on this specific car would be great. Or if you can point me to some "quadrajets for dummies" website or something....

Thanks!

Marc 85Z28

It's a second gen Camaro diagram, but it will work for what you need to do. Some of that diagram may not make sense because of possible deleted items like the TVS, but hopefully it gives some direction.

Any port below the throttle plates, not the air valve, is full manifold vacuum. Above the throttle is timed, or ported vacuum. You can use either depending upon how you want to setup the car.

Get Doug Roe's book on QuadraJets. You'll thank me later

Checkerbelly

Cool,thanks man. I'll look for that book.

Right off the bat I can tell you that I think he got rid of the EFE all together and plugged the distributor vacuum hose into the EGR valve connection. And the EGR valve is connected somewhere else - don't remember.
If those are all manifold vacuum I guess it wouldn't matter. That makes sense to me.

I don't have that many connections to my canister. There's a canister control valve that has a bunch of hoses coming and going, that is supposed to be associated with the CCC carb.

I guess the next step is to check my timing to see if the vacuum advance is functioning...

qdr

I have a 85 with the 4-barrel, 5 sp. that is 100% stock. It has never been messed with and all maintenance and reparirs were done by the Chevy dealer. I will have the car at my house next week. If you still need some information on the vacuum lines, I can look at mine and see if I can help.

Don't mess with it any more than has already been done, as this is a very rare engine combination for an 85.