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I have a 1992 F150 4x4 super cab with a 5.0. Looking under the hood, on the passenger side, beneath the batter, there is something that I have not been able to find online as to what it is. Found a post on YouTube where the guy was replacing vacuum lines. He said it was emissions related. My vacuumed line doesn’t connect to anything.
What is this? The vacuum line isn’t connected to anything. I looked everywhere and could not find any a vacuum hose it would connect to.
The bottom circle is the charcoal canister. I cannot tell where the hose in the top circle goes. There should be a hose that goes to throttle body from there and another that goes to the gas tank(s).
Ah, didn’t realize that was the charcoal canister. It has a rubber bend, then to a plastic straight run to the end. But there is no other vacuum hose on the end. I saw something on Youtube where a guy had his running to the intake. My intake has a hose on it connecting to the coffee can on the wheel well.
I do have the canister purge valve. One side connects to the intake, the other side connects to the coffee can. Not the charcoal thing by the battery on the front of the truck. Should it?
The lower one goes to the gas tank Pulled the plastic tub from behind the other hose I have the canister purge valve
I do have the canister purge valve. One side connects to the intake, the other side connects to the coffee can. Not the charcoal thing by the battery on the front of the truck. Should it?
The canister purge allows fuel vapor from the charcoal canister on the frame rail to be vented into the intake where it can be burned. There would be no reason to vent vacuum from the “coffee can”/ vacuum reservoir into the throttle body.
Surfed tonight. Found the following. My coffee can has 3 vacuum lines. One of them is the one that goes to the charcoal canister at the front of the truck below the battery. Do some coffee cans have 3 connections? I will remove my vacuum lines to the coffee can on Friday and inspect it.
this coffee can only shows 2 vacuum lines.
Only two of the ports look like they are real ports
Where does it show that? TAB is thermactor air bypass for the air injection system. Look like it goes to a valve for that system. Not the same as the fuel vapor system.
The coffee can looking vacuum reservoir is used for the EGR and Thermactor systems. It has no interaction with the fuel system's EVAP emission function. As you found there are frequently three ports on the coffee can looking reservoir but only two are functional. Someone has rigged your truck by re-routing the EVAP line to that coffee can looking reservoir. I assume the errant hose is plugged into the plugged port of the coffee can vacuum reservoir.
Only two of the ports look like they are real ports
That stud "keys" the connector so that source vacuum from the manifold (which varies) goes to the correct side & constant vacuum is on the other (where all the things that need operate on constant vacuum are plumbed).
