My 89 Fuel Vapor Line Connected Directly To Intake

Erick30150

Active User
Mar 13, 2017
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Just got me an 89 5.0 come to inspect it I realized that the fuel vapor line is connected directly to the intake instead of being on the canister and purge valve I want to know if this would cause problems at all the idle is a little High but if I take off the lines and block them off the idle gets worse...
 
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mustangFoxFordVacuumDiagram.jpg


Thank you tmoss & stang&2birds
 
I know how to route them and all but my only question is would there be a problem with the line from the fuel tank being directly connected to the intake. I will get the cansiter soon.
 
Yes, it will cause problems
ex·plo·sion
[ikˈsplōZHən]
NOUN
  1. a violent and destructive shattering or blowing apart of something,
Actually, I doubt that will happen but its not the way you want to vent your fuel tank, I would have to think the vapors being sucked into the intake will effect how it runs.
 
Here's some factual help...

Code 85 CANP solenoid - The Carbon Canister solenoid is inoperative or missing.

Revised 11 –Jan_2015 to add warning about vacuum leaks due to deteriorated hose or missing caps on vacuum lines when the solenoid is removed.

Check vacuum lines for leaks and cracks. Check electrical wiring for loose connections, damaged wiring and insulation. Check solenoid valve operation by grounding the gray/yellow wire to the solenoid and blowing through it.
The computer provides the ground for the solenoid. The red wire to the solenoid is always energized any time the ignition switch is in the run position.

If you disconnected the carbon canister and failed to properly cap the vacuum line coming from under the upper intake manifold, you will have problems. You will also have problems if the remaining hose coming from under the upper intake manifold or caps for the vacuum line are sucking air.

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.

Connecting the gas tank vent line directly to the intake manifold will result in fuel vapor being constantly sucked into the intake manifold. There is unmetered fuel that the computer cannot adjust for. The result is poor idle and poor fuel economy.

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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.

The purge valve solenoid should be available at your local auto parts store.

Purge valve solenoid:
smp-cp402_df_xl.jpg



The carbon canister is normally mounted on the passenger side frame rail near the smog pump pulley.
Carbon Canister:
903_AIRTEX%20_pct_2F%20WELLS_7310014_1.jpg
 
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If they eliminated the evap canister. They probably would smell gas fumes. So most likely plugged it into the intake to get rid of smell.

Its going to suck air from the fuel tank and fumes. So it could cause issues with idle.
 
You can keep same thread, that way people can go back and see your combination and previous work done.
Do a base idle reset.
Check out the surging idle checklist in the 5.0 tech/how to threads
Jrichker and others have put together this section to help with common problems and modification tips,
 
Thanks for the help everyone I got every thing hooked up right but still have some slight idle issues but will post new thread on that

You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 200,000 hits, which indicates it does help fix idle problems quickly and inexpensively.