Tori Lynne

A couple of weeks ago I bought my 85 firebird. The line going into the top of the charcoal canister was disconnected and plugged off with a bolt. My dad took the bolt out and that line shot gas in his face. We hooked the line back to the canister and now when I drive my car for 30 mins it starts running ruff....when it gets to an idol the car just dies.. with the line plugged off my car runs really rich and smells like gas...we changed the solenoid on the top of the canister when we hooked it all back up....Now we are at a loss on what to do. does any one know how to fix this or what could be wrong with it?
Thanks for your time,
-Tori Lynne

Duck

Hi Tori - welcome to TGO, you'll find this site a great resource for your Third Gen car. How about some more information about your firebird. V8, V6? It's quite possible issues other than the cannister are present. Has the car received a tuneup and check of the fuel pressure and engine sensors? Also, I'd recommend using the "search" function on the website in the "general" engine section and reading through the threads, you might find someone else that had the exact same problem as you're having.

From the Chilton book:

charcoal canister ECC - Evaporative Emission Control (EEC) Systems

The Evaporative Emission (EVAP) control system used on all vehicles is the charcoal canister storage
method. This method transfers fuel vapor from the fuel tank to an activated carbon (charcoal) storage
device (canister) to hold the vapors when the vehicle is not operating. When the engine is running,
the fuel vapor is purged from the carbon element by intake air flow and consumed in the normal
combustion process.

Removal of the vapors from the canister is accomplished by a solenoid operated bowl vent or vacuum
operated purge valve mounted on the canister. In addition to the fuel system vents and canister, the
fuel tank requires a non-vented gas cap. The domed fuel tank positions a vent high enough above the
fuel to keep the vent pipe in the vapor at all times. The single vent pipe is routed directly to the
canister.

These systems commonly use an in-line EVAP pressure control valve as a pressure relief valve. When
vapor pressure in the tank exceeds approximately 0.7 psi, the diaphragm valve opens, allowing vapors
to vent to the canister. Once the in tank pressure drops below 0.7 psi, the valve closes causing
vapors to be help in the tank.

If the EVAP system is not functioning properly, any one of the following conditions may be as result:
Poor idle, stalling, and poor driveability can be caused by:

Inoperative purge solenoid valve
Damaged canister
Hoses split, cracked or not connected to the proper tubes
Evidence of fuel loss or fuel vapor odor can be caused by:
Liquid fuel leaking from the fuel lines
Cracked or damaged canister
Inoperative canister control valve

Disconnected, misrouted, kinked, deteriorated or damaged vapor hoses or control hoses.
If the solenoid valve is open, or is not receiving power, the canister can purge to the intake
manifold at the incorrect time. This can allow extra fuel during warm-up, which can cause rough or
unstable idle.


Operation

This system reduces the amount of gasoline vapors escaping into the atmosphere. Some models employ a
purge control solenoid which is controlled by the ECM, to open and close the EEC system. Other models
use a canister mounted vacuum purge valve; when the engine vacuum reaches a certain pressure, the
valve opens allowing the gas vapors to be drawn off to the carburetor for burning.
Carbureted models use an exhaust tube from the float bowl to the charcoal canister; fuel injected
models eliminate the fuel bowl tube (as no float bowl is used on fuel injection systems). Fuel vapors
from the gas tank travel from the tank to the vapor canister, where they are collected. Although the
system varies from vehicle-to-vehicle, the operations are basically the same.


Testing Tank Pressure Control Valve

Using a hand-held vacuum pump, apply a vacuum of 15 in. Hg. (51 kPa) through the control vacuum
signal tube to the purge valve diaphragm. If the diaphragm does not hold 5 in. Hg. at least for 10
seconds, the diaphragm is leaking. Replace the control valve.

With the vacuum still applied to the control vacuum tube, attach a short piece of hose to the valve's
tank tube side and blow into the hose. Air should pass through the valve. If it does not, replace the
control valve.

Tori Lynne

My car is automatic, V-6. I have another question, the bracket on my left headlight is broken. Can I just replace the bracket, or do I have to replace the whole headlight?

jackballs529

Hey Duck - Good info on the Purge canister functionality. I have also been chasing a rough/stumby idle as well. I have not done the pressure test yet, couldn't you just yank the lines from the canister and plug them with your fingers to see it the idle gets better?

RandyM1969

I had my bracket welded. Instead of buying a new one