How to purge evap canister with aftermarket ecu?
08-31-2014, 05:40 PM
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Car: 1988 Firebird Formula WS6
Engine: 305 tpi lb9
Transmission: 5 speed
Axle/Gears: 3.45
How to purge evap canister with aftermarket ecu?
I always seem to have alot of pressure in my fuel tank that escapes when opening the cap and smell of fumes under the hood by the canister. The tank pressure has been like this forever even before I installed an aftermarket ecu without provisions for emmisions control but the fumes by the canister are worse now i think. Is there a vacuum controlled purge valve say for a carbuerated application that will work to purge my evap canister? I still have my canister but its not hooked up to the throttle body right now since I figured whats the point if the ECU I have cant even purge it. I dont want to remove the canister but starting to think its a bad idea to leave it there if its never being purged.. Any ideas on a manual way to purge the system so I can keep the fumes out of my engine bay?
09-01-2014, 12:25 PM
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Car: 1989 IROC & ROLL-Z
Engine: L98 Vortec FIRST TPI
Transmission: T56, Mech Speedo
Axle/Gears: G92 J65 3.27
Re: How to purge evap canister with aftermarket ecu?
I know my car (89 350tpi) has a check vent on the tank. If pressure builds past a certain point it releases. Not sure if your car has one, but mine is located almost right in front of my rear drivers coil spring.
It is not hard to take apart and clean, or cut a couple turns out of the coil so it opens at a lower pressure.
Just an idea
Looks like this.
It is not hard to take apart and clean, or cut a couple turns out of the coil so it opens at a lower pressure.
Just an idea
Looks like this.
Last edited by Keoman; 09-01-2014 at 10:12 PM.
09-01-2014, 05:54 PM
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Car: check
Engine: check
Transmission: check
Re: How to purge evap canister with aftermarket ecu?
The pressure in the tank is normal. The 'mushroom' valve posted above is more of an air inlet valve (as fuel gets used), but will also act as an excessive pressure relief valve.
Saying that! The CCP system vapor control valve opens at a lower pressure then the tank mushroom valve. So tank pressure (fumes) in a working system goes to the charcoal canister.
As for getting the CCP system going. Look at trucks of this era, many ran CCP systems without the solenoid. Easy enough to swap in.
The #1 thing to be sure of: do connect the purge hose to the throttle body where there is ported vacuum. That is, vacuum that is only present when the throttle blades are open some from idle.
RBob.
Saying that! The CCP system vapor control valve opens at a lower pressure then the tank mushroom valve. So tank pressure (fumes) in a working system goes to the charcoal canister.
As for getting the CCP system going. Look at trucks of this era, many ran CCP systems without the solenoid. Easy enough to swap in.
The #1 thing to be sure of: do connect the purge hose to the throttle body where there is ported vacuum. That is, vacuum that is only present when the throttle blades are open some from idle.
RBob.
09-01-2014, 07:20 PM
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Car: 1988 Firebird Formula WS6
Engine: 305 tpi lb9
Transmission: 5 speed
Axle/Gears: 3.45
Re: How to purge evap canister with aftermarket ecu?
The pressure in the tank is normal. The 'mushroom' valve posted above is more of an air inlet valve (as fuel gets used), but will also act as an excessive pressure relief valve.
Saying that! The CCP system vapor control valve opens at a lower pressure then the tank mushroom valve. So tank pressure (fumes) in a working system goes to the charcoal canister.
As for getting the CCP system going. Look at trucks of this era, many ran CCP systems without the solenoid. Easy enough to swap in.
The #1 thing to be sure of: do connect the purge hose to the throttle body where there is ported vacuum. That is, vacuum that is only present when the throttle blades are open some from idle.
RBob.
Saying that! The CCP system vapor control valve opens at a lower pressure then the tank mushroom valve. So tank pressure (fumes) in a working system goes to the charcoal canister.
As for getting the CCP system going. Look at trucks of this era, many ran CCP systems without the solenoid. Easy enough to swap in.
The #1 thing to be sure of: do connect the purge hose to the throttle body where there is ported vacuum. That is, vacuum that is only present when the throttle blades are open some from idle.
RBob.
09-02-2014, 08:12 AM
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Car: check
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Re: How to purge evap canister with aftermarket ecu?
If the solenoid is normally open then you can use it as is. Just need to connect the purge line to the proper port on the TB. Need to check the solenoid first as GM used both NO and NC solenoids on these cars.
RBob.
RBob.
