Canister Vacuum

Puntuation goes a long way here

What's puntuation?

to punt or not to punt, that is the question

Uh.... punt

One hose goes to a solenoid valve and then to a connector on the bottom of the intake plenum. The other hose goes to the breather valve on top of your fuel tank.

Are you not running a charcoal canister?

I was more curious just to be sure what was capped.. Have you hooked up a vacuum gauge?

nenotch402 said:

ok so ive been chasing down vacuum leaks on my recently purchased notch so i replaced my upper intake gasket thinking thats where my leak was from and replaced all my vacuum lines to the egr and stuff but ive noticed one line im not sure where it goes its coming off the canister and its in a loom with some other wires can some tell me where this plugs into on the intake or have a pic thanks

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If there ever was an Interstate highway called "Grammar", this would be a multicar pileup...

Now to answer your question, read the Code 85 description below...

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

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.

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

Purge valve solenoid:



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

Heres my cannister vacuum

Code 84 EGR Vacuum Regulator failure – Broken vacuum lines, no +12 volts, regulator coil open circuit, missing EGR vacuum regulator. The EVR regulates vacuum to the EGR valve to maintain the correct amount of vacuum. The solenoid coil should measure 20-70 Ohms resistance. The regulator has a vacuum feed on the bottom which draws from the intake manifold. The other vacuum line is regulated vacuum going to the EGR valve. One side of the EVR electrical circuit is +12 volts anytime the ignition switch is in the run position. The other side of the electrical circuit is the ground path and is controlled by the computer. The computer switches the ground on and off to control the regulator solenoid.


Some basic theory to clarify how things work is in order…

EGR System theory and testing

Revised 29-Sep-2013 to add code definitions for EGR sensor and EVR regulator.

The EGR shuts off at Wide Open Throttle (WOT), so it has minimal effect on performance. The addition of exhaust gas drops combustion temperature, increases gas mileage and reduces the tendency of the engine to ping. It can also reduce HC emissions by reducing fuel consumption. The primary result of EGR usage is a reduction in NOx emissions. It does this by reducing the amount of air/fuel mixture that gets burned in the combustion process. Less air from the intake system means less air to mx with the fuel, so the computer leans out the fuel delivery calculations to balance things out. This reduces combustion temperature, and the creation of NOx gases. The reduced combustion temp reduces the tendency to ping.

The computer shuts down the EGR system when it detects WOT (Wide Open Throttle), so the effect on full throttle performance is too small to have any measurable negative effects.

The EGR system has a vacuum source (line from the intake manifold) that goes to the EVR, computer operated electronic vacuum regulator. The EVR is located on the back of the passenger side shock strut tower. The computer uses RPM, Load. and some other factors to tell the EVR to pass vacuum to open the EGR valve. The EGR valve and the passages in the heads and intake manifold route exhaust gas to the EGR spacer (throttle body spacer). The EGR sensor tells the computer how far the EGR valve is open. Then computer adjusts the signal sent to the EVR to hold, increase or decrease the vacuum. The computer adds spark advance to compensate for the recirculated gases and the slower rate they burn at.

The resistor packs used to fool the computer into turning off the CEL (Check Engine Light) off are a bad idea. All they really do is mess up the data the computer uses to calculate the correct air/fuel mixture. You can easily create problems that are difficult to pin down and fix.



Troubleshooting:
There should be no vacuum at the EGR valve when at idle. If there is, the EVR (electronic vacuum regulator) mounted on the backside of the passenger side wheelwell is suspect. Check the vacuum line plumbing to make sure the previous owner didn’t cross the vacuum lines.

Diagram courtesy of Tmoss & Stang&2birds. (the diagram says 88 GT, but the EGR part is the same for 86-93 Mustangs)


The EGR sensor is basically a variable resistor, like the volume control on a radio. One end is 5 volt VREF power from the computer (red/orange wire). One end is computer signal ground (black/white), and the middle wire (brown/lt green) is the signal output from the EGR sensor. It is designed to always have some small voltage output from it anytime the ignition switch is the Run position. That way the computer knows the sensor & the wiring is OK. No voltage on computer pin 27 (brown/lt green wire) and the computer thinks the sensor is bad or the wire is broken and sets code 31. The voltage output can range from approximately .6-.85 volt. A defective or missing sensor will set codes 31 (EVP circuit below minimum voltage) or 32 ( EGR voltage below closed limit).

The EVR regulates vacuum to the EGR valve to maintain the correct amount of vacuum. The solenoid coil should measure 20-70 Ohms resistance. The regulator has a vacuum feed on the bottom which draws from the intake manifold. The other vacuum line is regulated vacuum going to the EGR valve. One side of the EVR electrical circuit is +12 volts anytime the ignition switch is in the run position. The other side of the electrical circuit is the ground path and is controlled by the computer. The computer switches the ground on and off to control the regulator solenoid. A defective EVR will set codes 33 (insufficient flow detected), 84 (EGR Vacuum Regulator failure – Broken vacuum lines, no +12 volts, regulator coil open circuit, missing EGR vacuum regulator.)


EGR test procedure courtesy of cjones

To check the EGR valve:
Bring the engine to normal temp.

Connect a vacuum pump to the EGR Valve or see the EGR test jig drawing below. Connnect the test jig or to directly to manifold vacuum.

Do not connect the EGR test jig to the EVR (Electronic Vacuum Regulator).

Apply 5in vacuum to the valve. Using the test jig, use your finger to vary the vacuum

If the engine stumbled or died then EGR Valve and passage(there is a passageway through the heads and intake) are good.

If the engine did NOT stumble or die then either the EGR Valve is bad and/or the passage is blocked.

If the engine stumbled, connect EGR test jig to the hose coming off of the EGR Valve.
Use your finger to cap the open port on the vacuum tee.
Snap throttle to 2500 RPM (remember snap the throttle don't hold it there).
Did the vacuum gauge show about 2-5 in vacuum?
If not the EVR has failed

EGR test jig


To test the computer and wiring to the computer, you can use a test light across the EVR wiring connectors and dump the codes. When you dump the codes, the computer does a self test that toggles every relay/actuator/solenoid on and off. When this happens, the test light will flicker. If the test light remains on the computer or the wiring is suspect.

To check the EVR to computer wiring, disconnect the EVR connector and connect one end of the Ohmmeter to the dark green wire EVR wiring. Remove the passenger side kick panel and use a 10 MM socket to remove the computer connector from the computer. Set the Ohmmeter to high range and connect the other ohmmeter lead to ground. You should see an infinite open circuit indication or a reading greater than 1 Meg Ohm. If you see less than 200 Ohms, the dark green wire has shorted to ground somewhere.

nenotch402 said:

lol i think he means punctuation and im sorry i didnt realize i was back in english class

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There are good reasons the taxpayers provided you with the "option" of learning at their expense. Being a literate member of society is important. It is hard to help if you are unclear. Grading here is simply pass/fail by if you can be understood. There will be errors, especially if you use a mobile device. But please try to pass and I'll try to help.

Right now, jrichker has you on the right path.

Typing on a smell phone stinks. I am a little sorry for the rant. But I think texting will be the end of good communication skills. You can probably tell what one of my professions is.