emission control system FUEL TANK Vapors ? (1 Viewer)

love2fly

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Question on the ECS system on a FJ40 with a fuel tank expansion check valve.
I found that my 1982 FJ40 fuel tank vapor control valve ( Check Valve) that's found on the Toyota ECS was missing instead a continuous hose was in place, no check valve at all. It was also notice that the fuel cap had a very small hole drilled into the center. My question can this be one of the main reasons a 2F engine will fail emissions resting with a moderate reading in the CO and HC area.
So, I was thinking that this maybe the reason for the readings we are getting. Raw fuel fumes are being continuously pulled though the charcoal canister into the carburetor being that the system is not closed but should be a closed system until pressure build up in the tank were the check valve would open and burn the vapors of fuel. Yes the gas cap for what ever reason passed? Rig has no other emission not even a CAT, all stock. From Australia.

We did get it to pass but after 4 attempts (how I do not know), so we are now investigating all possibilities now before our next visit on the 1st of 2022.

Cheers

Test 1-2.jpg






emission control system limits the amount of noxious gas released from the car into the environment. The car components that release gases are the fuel tank, carburetor, crankcase, and exhaust. These components are also necessary to run the car. The emission control system isolates and contains the gases within a closed system. This system is often referred to as the EVAP system.
The components of the emission control system include fuel fill cap, vapor recirculation tube, fuel tank vapor control valve, evaporative emission canister, fuel tank pressure sensor, canister vent valve, evaporative two-way valve, and the evaporative canister purge valve.
 

ToyotaMatt

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Question on the ECS system on a FJ40 with a fuel tank expansion check valve.
I found that my 1982 FJ40 fuel tank vapor control valve ( Check Valve) that's found on the Toyota ECS was missing instead a continuous hose was in place, no check valve at all. It was also notice that the fuel cap had a very small hole drilled into the center. My question can this be one of the main reasons a 2F engine will fail emissions resting with a moderate reading in the CO and HC area.
So, I was thinking that this maybe the reason for the readings we are getting. Raw fuel fumes are being continuously pulled though the charcoal canister into the carburetor being that the system is not closed but should be a closed system until pressure build up in the tank were the check valve would open and burn the vapors of fuel. Yes the gas cap for what ever reason passed? Rig has no other emission not even a CAT, all stock. From Australia.

We did get it to pass but after 4 attempts (how I do not know), so we are now investigating all possibilities now before our next visit on the 1st of 2022.

Cheers

View attachment 2656354





emission control system limits the amount of noxious gas released from the car into the environment. The car components that release gases are the fuel tank, carburetor, crankcase, and exhaust. These components are also necessary to run the car. The emission control system isolates and contains the gases within a closed system. This system is often referred to as the EVAP system.
The components of the emission control system include fuel fill cap, vapor recirculation tube, fuel tank vapor control valve, evaporative emission canister, fuel tank pressure sensor, canister vent valve, evaporative two-way valve, and the evaporative canister purge valve.


do u need help sourcing the check valve ?

here you are , here is a OEM toyota gas cap too , if you suspect its one way venting feature is faulty too ,

better safe then sorry



 

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