pvollman

Have a 1992 Z03 Heritage with a 305, TBI. My question is; under the carbon cannister there is a vacuum pod with a vacuum hose on it not plugged into anything? Where does the vacuum hose plug into? I have searched vacuum diagrams and have dealer books but cannot find where this goes. The car does not have cruise control. Any help would be appreciated.

vetteoz

iTrader: (13)

There should be other items in the same area with vac lines going to them, the line in question should go to same vac feed as those, usually with aT or Y fitting.The vac supply comes from the TB.

pvollman

I saw a Y at the carbon cannister above it. It has lines hooked to it already. This vacuum pod is actually mounted underneath the airdam tucked up underneath the cannister in between where it mounts. Carbon cannister; then metal mounting base; then vacuum pod. Its had something hooked to it before; still has a piece of line hooked to it with tape on the end. If someone could tell me if it goes to that Y that has the plastic connector on it it would be great. This Z has california emissions; and has no label under the hood for line routing. So I have no diagram to go by. Any help would be appreciated.

Zwrench

I'm no expert on the '92 Camaro but, that sounds like the vacuum 'reservoir' for the HVAC controls. If it's anything like my car, there should be a plastic vacuum line running from that 'pod' through the firewall to provide vacuum to the heater controls.

If the pod only has one vacuum fitting then it probably tees off somewhere near the engine before going through the firewall.

pvollman

Thanks for the reply; I'll look this morning to see if I can find where it connects? I always wondered why when I floored it that I would loose my air circulation out of the vents...now I know why. Just wish I knew where it connected? The piece of vacuum line still connected to it is about 8 inches long and has tape on the end...go figure...

Zwrench

I would look at where the vacuum line comes out of the firewall. It's just to the right (as you're looking at it) of the heater hoses. It should be bundled with the HVAC wiring. My guess is that vacuum hose is connected directly to a vacuum fitting on the engine.

Get a 't' fitting and run a new line to the vacuum ball and you should be set... unless the vacuum ball is damaged or leaking, that is.

vetteoz

iTrader: (13)

At rear of engine there should be a vac line from the intake to a check valve.From there it splits; one line inside to the HVAC control , the other to the vac canister.
You obviously only have direct engine vac to the controls which is why your vents change when engine vac drops.
You can get a generic valve from NAPA or similar and run a new line to the canister
Vette shown but F-body basically the same

pvollman

Thanks...going outside now to see if I can find it...more to follow.

Chevy86 IROC-Z

iTrader: (17)

that HVAC line also can be hidden. it may not run directly into the firewall. I have a 86 IROC Z and my HVAC vac line is popping out of the wiring harness which then runs into the firewall. Look at your wiring harness on the passenger side, maby there will be a small vac line popping out. I spent like 3 weeks trying to figure out my vac. line issue. Ive got a lengthy thread about it and the member here that goes by the name of vetteoz was a huge help. Thanks vetteoz .

pvollman

Sorry it took so long to reply; been busy. Anyway; I went and got a two port air check valve and 10 feet of vacuum line. Ran everything the way you guys described and it is now fixed. I no longer loose circulation out of the air vents when I floor the car...its great! Now I can drive normally and stay cool with A/C. Thanks again for all the help and suggestions; I wouldnt know what to do without you guys!

vetteoz

iTrader: (13)

As the A Team used to say
"Love it when a plan comes together"

Chevy86 IROC-Z

iTrader: (17)

Chevy86 IROC-Z

iTrader: (17)

HEY pvollman, how do you like this unusual weather? Your only 46 miles away from me. I live in Holtville, CA. Sup bro. I see that your issue has been solved. Good deal. Hey, maby we can drive up and down the I-8,,,,when I finally fix my IROC-Z. Peace bro.