Where does this vacuum hose go?

84 xjs. There are two vaccum hoses coming off of the top of the left (driver) intake manifold right next to each other. one goes to a canister behind the left headlight. The other one goes towards the back of the engine but is unplugged and I can’t find what it is supposed to plug to. Can someone help me?

There are two vacuum control valves to vent the carbon canister. The two hoses come off of the top of the left throttle body and are staggered so the valves do not open at the same time. Both control valves should be right beside each other.

Thanks. I was looking in totally the wrong place.
I just replaced the water pump and am in the process of replacing the radiator. I cannot remember where these two wires plugged on. Do you know? They dont go to the the radiator or fan and I don’t see any open connectors.

@Kirbert do you know what that wire is?

I’d be guessing, but it looks kinda like the wires that originally went to the Supplemental Air Valve.

If you’re talking about the little valve that plugs in the back of the right air box that already has wires on it. So I’m still at a loss as to where these go. Does anyone have an idea of where to look? It comes around the right side of the engine and can reach almost to the left side.

I can see that one wire is Black but I can’t tell from your picture the color of the second wire. What color is the second wire?


light Orangish or tan with a white stripe. Has male spade connector

Cold start injector?

How about the two wires to the Purge Control Valve for the carbon canister? It has a Black and a Pink/White wire.


If Cold start injector is the blue thing to the front of the right airbox that has a connector on it similar to the fuel injector connectors.

If your talking about the canister behind the left headlight, that wire would not reach there. But I only see vaccum hoses going there. I looked around but couldn’t see any electrical connections. It reaches about as far left as the power steering pump so I was thinking the connection was up around the ac compressor or radiator. but the radiator, transmission cooler or ac condensor have no wires. Is the hood supposed to have a light under it because mine doesn’t. Maybe someone left it lying and it was not connected. It would need to connect to a female spade connector and I don’t see any of those anywhere.

So I followed the wire back behind the air filter and it splits and one path does go to the Supplemental Air Valve that plugs into the back of the air cleaner but it it also continues on back to the firewall. So what else hooks to the same connection as the supplemental air valve?

There’s a vacuum solenoid that controls vacuum to the advance mechanism. It’s supposed to operate at the same time as the SAV.

The Purge Control Valve (DAC2617) is a solenoid valve that is normally closed but opens when the car is started and intake manifold vacuum pulls the stored gas fumes from the carbon canister into the intake manifold to be burned. It has two wires going to it, a Pink/White one and a Black one and it has female connectors. It should be in t he plumbing associated with the carbon canister but in the engine bay.

I don’t know where in the world you are located, but if you are in the USA I believe that your car should have originally had one. I suppose that it could have been removed along the way.


So the wire comes out of a wiring harness going across the back top of the engine, goes to the SAV on the air box and then continues on out the front of the engine which is the wire I’m trying to find connection for. Where about would the vaccum solenoid be? Is there anything else that connects to the same circuit?
It wouldn’t be connected to the purge control value as well would it?

One thing that keeps crossing my mind is that your photo shows a male blade terminal.Could it be that the male terminal should be plugged in to a diode (with the female configuration) which is then connected to the two relays on the top of the radiator which trigger the SAV when the A/C is on?

I don’t remember removing any relays when I took the radiator out. It look like according to this post it was only 85 and later that might have had those

Yep, those are the ones. Too bad , because everything else seems to fit!

I’m thinking the longer leads were supposed to go to the SAV. The shorter leads were supposed to go to a vacuum solenoid under the RH intake manifold, controlling vacuum to the vacuum regulator and the vac advance.

I think the purge control valve should be at the LF corner of the engine somewhere.