so, i go to change the fuel filter on my girl's '89 RS...get under there lines are rusted bad...hit the nuts with some wd40 no luck...turning it i happen to kink the rusted line before the filter(the gas tank side) and gas starts squirting....ok i turn it back and it makes it a pretty small leak...Ya nice now i either gotta cut the tube and put a rubber hose in place or just get new tubing measure it out...bend it cut it and put it in place. Well i figured id give just replacing a small section with a rubber hose first. Oh ya to stop the leak i opened the gas cap which supposely "realeases the pressure" right? I start to cut twist bend stuff in the small space i got to get the cutting tool up there and now gas is pouring out...After i released all the presure the day before i put the gas cap back on...go up to undo it and more pressure comes out. Let me remind you car has not been started or on the on position so the fuel pump did nothing. Realease all the pressure hoping the fuel will stop being pumped towards the engine...no luck just keeps draining. Try this a few times over an hour...and the cap kept going psshhh likes there pressure in the lines? Im not understanding that. Am i some how making it siphon out the kinked line? I tighten the cap and let it sit and drain and it gets less and less came out and now i put a new drain pan under it and i had to go home...it got too dark. So ya whats up with that? Why is putting the cap on making it stop...and if taking the cap off realeasing the pressure making it suck more from the tank, im pretty confused. So anyway im gonna go back tommaro and not mess with the cap and just start cutting the tube...i doubt more will come out. But ya...i hate rust...anywere

So any suggestions or explanations for this junk...?

 

Its just like a gas can with the brether on the back . I had a this happen to me changeing the fule pump (on the block) had to work fast cap on or off same thing . I would try to jack the front of the car higher then the rear . Depending how close to the tank the leak is .

 

haha i just thought about that today when i was filling a power washer up with gas...i was like that HAS to be whats going on...thanks though and good advice with jacking the front of the car up. I just got off work and im heading over there now.

 

actually, wht it sounds like is a syphoning effect. putting gas cap on creates a vacuum keeping the fuel from flowing. removing the gas cap releases the vacuum formed thereby permitting it to syphon the gas out of the tank. jacking the front of the car up will not have much of an effect since the fuel filter is so close to the tank.