Okay I am thoroughly confused and baffled....please help me quick! I am replacing my fuel filter in my 89 TBI Camaro and something is very wrong. I took the pump fuse out and made sure pressure was gone... car wouldn't restart so I know the pump is off... also, I do not hear the pump running at all. So I open the line at the filter, expecting some fuel to come out. Yet the fuel will not stop coming out! The fuel just keeps coming out out of the line, like a strong steady stream, the pump side of the filter that is. IDK whats going on! How can fuel be draining from the tank? The pump is definitely not running. What is happening? Thnx in advance.. i really need to get this done before tonite.

Patrick DeGrosse JR.

 

you just need to remove (and keep out) any pressure in the system. Stick a screwdriver or something in the gas tank filler "flap" just to keep the system de-pressurized or...give a buddy a beer and have him stick his finger in the filler neck hole and just stand there LOL

 

well physics say things wont flow higher than they are, but if you have a full tank of gas it could be pushin out the fuel from the pressure like chevyboy said

 

Yep, Back in the day I was replacing a fuel filter on an 83 "I think" crossfire Vett. That sucker was full of gas and for 10 min It ran like a river. Talk about high!!! If you release some pressure by venting the tank It might stop or it might not. The best way to do it is get the car fairly low on fuel then pop the gas cap off and let all the fuel drain back into the tank for about 30min. By then only a little amount of fuel should spill out damaging less brain cells.\
SSC:lala:

 

When i replace the fuel filter (sucks), I pull the FP fuse and start the car and run it till it stalls. That should get a good amount of fuel out of the lines before you take the filter off.

 

Alright i just finished the job.. eyes still burn.. but its done.... gas was still flowin strong but oh well. Yea i relieved the pressure like you said but this fuel was definitely coming from the tank. IDK how that is possible but it undoubtedly was. The job is done but i'd still like to know why this happened? I mean that shoots physics right in the foot i'd say.... thnx guys

Patrick DeGrosse Jr.

 

well gasoline does weigh a decent amount per volume, so if you had a full tank of gas, the weight of the gasoline (pressure) is definately more than the weight of the atmosphere (pressure). so when you unhooked the fuel lines the pressure tries to equilize itself. that is my best way of thinking of a solution. I bet if you parked on a hill with the back of the car facing down it might not have leaked so much since the majority of the weight of the gas would be on the side of the tank instead of the bottom of it where the fuel pick up is. al I can say is doodoodoodoodoodoodoodoodoo ha, lol

 

The reason gas was still coming out was because there is still gas in the line. When you relieve the fuel pressure by taking off the gas cap, thats all it is; relieving fuel pressure. There will still be gas in the line its just won't spray all over the place when you take the filter off. I don't know about the gas tank being full affecting that much because if you look at the gas lines, right after they exit the tank, they curve UP along the perimeter of the rear wheel well before it gets to the filter. So really the gas coming out is the gas in the lines between that point and the fuel rails on the intake. If you stick a suitable container under there and leave it for 10 minutes, you can drain all the fuel out of the lines and you won't have cold fuel spilling all of your hands while you put the new filter on.

 

You know how a siphon works right? Well, theres only fuel in the line and the low point is where the filter is, so it just sorta flows right out. Getting an air bubble in the fuel line will stop the flow.

 

That's EXACTLY what I was gonna say!! Dang nabbit!!!

AJ

 

Yea the idea of a siphon crossed my mind but I didn't know how the pump worked and figured that it couldn't siphen through that. I guess thats what it had to have been because it definitely would have run the tank dry had i left it. I lost a good two gallons by the time I came back out and realized that it was still going Oh well... ya learn something new everyday. Tomorrow's project.. new EGR valve.. thanks again guys.

Patrick DeGrosse Jr.

 

same thing happened to me..i couldnt start the car because it ended up the fuel pump was dead but the gas wouldnt stop coming out so i got under there and tried to change them as fast as i could...gas was running down my arm, back, in my hair it was horrible. burned like a **** i finally got it done and ran inside and took a shower burned badddddddd

 

maybe i just lucked out....

I removed my gas filler cap, to relieve pressure (91 RS btw), with half a tank left.

Then crawled beneath and removed the filter....lost only the fuel that was in the filter and a minor amount in the lines..id say 1/2 cup to a full cup no more than that. Swapped filters and presto...

ah well.