Mystery vacuum line

[Squarescare]

Hey all

I have a 1987 v20 squarebody and theres a line running off the tbi that has a screw in it and for the life of me I cant figure out where its saposed to go, also getting occasional odb code 44 lean condition so im guessing its my vacuum leak. Pic attached. Guessing you guys will know right what it is

 

[fast 99]

Charcoal cannister?

 

[Squarescare]

Charcoal cannister?

Thats got a line from the fuel system i belive and everything is plugged into it

 

[skysurfer]

Three possibilities. Take the air cleaner off and post another pic.

 

[Squarescare]

Three possibilities. Take the air cleaner off and post another pic.

Done

 

[skysurfer]

Yours is arranged a little different than my '89 but they have the same ports. I have the right port going to the vacuum reg valve, (yours appears the same) the middle port goes to fuel evap, (shorter port by the fender) and the left port goes to pcv on the valve cover. Mine setup matches the emissions sticker so I know it's correct. It looks like your pcv is on the center port so fast 89 was correct with his charcoal cannister input.

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[Squarescare]

I wouldnt doubt mine is wrong but i already have line coming off the fuel system vent to the canister so im alittle confused ah well ill figure it out eventually

 

[gmbellew]

looks like PCV, Fuel Cannister, EGR, or MAP are your options based on skysurfer's image. if somebody has been messing with things, stuff could be on the wrong port

 

[skysurfer]

You have two lines on the charcoal cannister? One to the fuel tank and the other to the tbi?

 

[Turbo4whl]

From our library, no less than 3 different vacuum hose diagrams for a 5.7 in 1987.

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And a few more for the 5 liter engine that may also be in that truck.

 

[Squarescare]

You have two lines on the charcoal cannister? One to the fuel tank and the other to the tbi?

Ya heres some more pics theres a 3rd port on the canister and thanks turbo thats def gonna help,mine has 3 ports so im thinking its port J goes to air inj vavle wherever that is

 

[skysurfer]

All the cannisters are the same, two lines with a vent in the middle.

 

[Squarescare]

All the cannisters are the same, two lines with a vent in the middle.

Yep didnt know if that was a port or what ok then i think its j port off the tbi that goes to air valve

My canister is piped into A port but like i said it doesnt mean any of it was hooked up right but it seems to be with the exception of J port and i meant my TBI has 3 ports

 

[mtbadbob]

Yep, that 4th line goes to air pump. I also have an '87 V20 that has the air pump removed & the line plugged at TBI

 

[Squarescare]

Yep, that 4th line goes to air pump. I also have an '87 V20 that has the air pump removed & the line plugged at TBI

Should i bother with it then? I thought it may have something to do with my check engine code lean 44