Corona 1976 4age fuel line setup

[Corona4age]

Hello guys , 

          I have an 1976 toyota corona with 4age bluetop engine. The engine has been setup from the previous owner with charcoal canister deleted. Now I can smell fume every now and then when driving the car. I think the fuel line setup currently is incorrect in terms of venting fuel vapor. But I don't wanna do a lot of modification, so I have come up with an idea with less modification, using most of the existing parts. Could you please help me verify if my idea shown in the diagram is OK to go for? 

       

Existing setup: A T-way fitting is used, in between the filler overflown line, as a return line from the engine. 

                                   Inline fuel pump is used as depicted: working fine so I'll leave it as it is.

                                   The vent line just goes to a hardline routing to the rear chasis on the right side of the car. (which, I suspect, is where the fume comes from) 

                                    No breather to let the air in when the tank is in vacuum state (air probably gets in from the gas cap which is not completely seal due to its age) 

 

What I would do is: 

                            Putting a check-valve on a vent line to let the ambient pressure in when tank gets vacuum

                           Routing the vent line to the charcoal canister and set things up as the way it should be (will need new canister and run the vapor to the throttle body) or 

                           Routing the vent line to the same place where it was then connect a hose and route it underneath the car. 

 

Consideration: Emission control regulation is not an issue in where I'm from. 

                         Car is driven on weekend as hobby now a daily use. 

FORGIVE ME!!! for the scratchy things on the vent line (it is nothing just a line to the canister) 

                            

 

[altezzaclub]

Any chance fuel from the return line gets out under the cap??  Have you ever checked how much fuel comes out of the return line?  When I did I was surprised it was such a flood. Although I expect fumes from the vent pipe are the most likely culprit.

Your diagram seems fine, vent the system to a charcoal canister and burn it. Would you be better to vent it from the where your current return is, and put the return in the port you're planning the vent on??

From taking the fuel cap off at the gas station, do you think the tank is under vacuum or pressure??  I've often felt its a rush of vapour out of the tank, not a rush of air into it. I put it down to the return line feeding heated fuel back into the tank so its thermal expansion, but I'd like second opinions.

I'm running a different setup, the Ke70 fuel tank under the floor is more a pain, but I still smell raw fuel now and then.

Edited December 9, 2021 by altezzaclub

[Corona4age]

On 12/9/2021 at 7:20 PM, altezzaclub said:

Any chance fuel from the return line gets out under the cap??  Have you ever checked how much fuel comes out of the return line?  When I did I was surprised it was such a flood. Although I expect fumes from the vent pipe are the most likely culprit.

Your diagram seems fine, vent the system to a charcoal canister and burn it. Would you be better to vent it from the where your current return is, and put the return in the port you're planning the vent on??

From taking the fuel cap off at the gas station, do you think the tank is under vacuum or pressure??  I've often felt its a rush of vapour out of the tank, not a rush of air into it. I put it down to the return line feeding heated fuel back into the tank so its thermal expansion, but I'd like second opinions.

I'm running a different setup, the Ke70 fuel tank under the floor is more a pain, but I still smell raw fuel now and then.

very crystal clear for your diagram. I wish I could do the surge tank setup. But I may just leave mine as it is for now and may run the return and vent lines as you suggested. 

 

thanks