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vac line running from under upper intake is not hooked to anything it's just plugged

  • Thread starter Thread starter 90lxwhite
  • Start date Start date Sep 25, 2011

90lxwhite

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Aug 25, 2011
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Sep 25, 2011
#1
  • Sep 25, 2011
  • #1
Hey guys was tracing vac line and found one that runs from under the upper intake down to where the air intake goes and it isn't hooked up to anything it just has a bolt stuck into it to plug it. I think it's goes to the EGR system but I'm not sure. The charcoal canister is removed and it has a home made cold air intake on it. Should that line be running somewhere or is ok as is? The car isn't running right, still have that intermittent buck and chug and it isn't wanting to shift until like 2500 or I let off the throttle and 2k rpm. Im only getting 120 mi on a tank and it's running like 2k rpm or a lil higher in OD at like 65 or 70 where it used to run like 1500.
 

Mustang5L5

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Sep 25, 2011
#2
  • Sep 25, 2011
  • #2
If it's the vac line in front, then that runs down to the charcoal canister.

You may want to look into what the original owner did for the vent line that comes from the gas tank. Hopefully they didn't leave it open in the engine bay venting gas vapors under the hood which can be dangerous,


If you having issues with the way the car runs, first thing to do is pull the engine codes. Then go down the list attacking and correcting each one. When people start yanking things off like smog, egr, charcoal canister, etc...is when cars start running strangely.
 

BlackGT89

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Dec 16, 2002
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Sep 25, 2011
#3
  • Sep 25, 2011
  • #3
My car started having a cold start issue, fluctuating idle and a few other symptoms. Turns out it was this very vacuum line that was leaking. I stuck a plug on the nipple on the intake and plugged the line going to the canister until I can get to a parts store and get a new vacuum line.
 

jrichker

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Sep 26, 2011
#4
  • Sep 26, 2011
  • #4
Charcoal canister plumbing - one 3/8" tube from the bottom of the upper manifold to the rubber hose. Rubber hose connects to one side of the canister solenoid valve. Other side of the solenoid valve connects to one side of the canister. The other side of the canister connects to a rubber hose that connects to a line that goes all the way back to the gas tank. There is an electrical connector coming from the passenger side injector harness near #1 injector that plugs into the canister solenoid valve. It's purpose is to vent the gas tank. The solenoid valve opens at cruse to provide some extra fuel. The canister is normally mounted on the passenger side frame rail near the smog pump pulley.



It does not weigh but a pound or so and helps richen up the cruse mixture. It draws no HP & keeps the car from smelling like gasoline in a closed garage. So with all these good things and no bad ones, why not hook it up & use it?


The purge valve solenoid connector is a dangling wire that is near the ECT sensor and oil filler on the passenger side rocker cover. The actual solenoid valve is down next to the carbon canister. There is about 12"-16" of wire that runs parallel to the canister vent hose that comes off the bottom side of the upper intake manifold. That hose connects one port of the solenoid valve; the other port connects to the carbon canister.

Purge valve solenoid:



The carbon canister is normally mounted on the passenger side frame rail near the smog pump pulley.
Carbon Canister:
 
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