94 Won’t Start Unless Gas Tank Cap is Loosened (1 Viewer)

[meatloaf]

My brothers truck was running fine until two days ago. He had front bushings and rear panhard changed along with an alignment after we swapped in an Ironman 2.5” lift. For two days in a row the truck would not start unless he would loosen up the gas tank cap. Could we or the alignment shop messed something up under the truck? Coincidence? Truck had been starting fine before this

 

[jonheld]

Replace the charcoal canister.
The clogged canister is causing overpresurization of the fuel tank.

 

[gummycarbs]

When you remove the gas cap, does it blow air out and reek of gasoline, or does it suck air in?

If it's not blowing fumes out, it might be that the check valve in the gas cap is clogged. Somewhere there's a thread showing how you can take the gas cap apart, but I can't seem to find it. I cleaned mine out and it was packed with crud.

 

[shocktower]

Replace the charcoal canister.
The clogged canister is causing overpresurization of the fuel tank.

Also a bad gas cap

 

[jonheld]

Also a bad gas cap

Possiby. New OEM gas cap is only about $22.
77310-12140

 

[shocktower]

Possiby. New OEM gas cap is only about $25.

Yeah I had that issue when mine was a gasser, and it fixed it . But now I have a no pressure system with diesel and I am really happy

 

[jonheld]

Yeah I had that issue when mine was a gasser, and it fixed it . But now I have a no pressure system with diesel and I am really happy

I had this happen on the way up to the Eisenhower Tunnel in my 91. Had to open the gas cap and it vented for a good 10 minutes. I disconnected the tank line to the charcoal canister to continue my trip. Replaced the canister when I got home, but it had already fractured the fuel filler line.

A clogged canister is a bad thing.