Will this work to relieve fuel pressure?

[Roboskittle]

I did say it was possible if the conditions were set just right. Guess I was a little off on what kind of temps a cigg produces though. I am not going to argue that point at all I know it can happen and I appreciate your concerns for my life. I take the risks and I know it can lead to possible dangerous situations. However let me let you know that whenever I pull off fuel lines hardly any gas comes out of the fuel lines at all. There is no spraying action at all and I may get 2 to 3 ounces at best total out of the fuel lines. More fuel comes out of the filter after I have it off than comes out of the actual fuel lines.

Again I know the risks and have actually lost a shop and multiple cars and thousands of dollars worth of tools due to a fire caused by fuel. The festiva in my Sig is one of them. It was however the fumes that were ignited and I was in no way shape or formed involved with anything that caused the fire. My friend was draining gas into a 5 gallon bucket which kicked up fumes and the hot water heater which was 3 ft behind the gas tank he was draining ignited the vapors. It was quite the experience and I thought I would never ever ever get over my fear of gasoline after that happened. I was there but again I had nothing to do with what caused the fire. One of the biggest things I learned from this was to do all fuel supply maintenance out doors away from un-realized ignition sources.

I am not arguing with you and I will keep everything you have shown me in mind. Some of the things I do are stupid I deffinately will not argue that. I am not however going to change my practices because I feel that I am very safe and try not to shower myself with gasoline lol. Thanks for the heads up, Jeremiah.

[Pu241]

^^^
No argument here, I just do not want to visit another burn ward, EVER!
Especially, when something could have been done to prevent it!

I just have to use this emoticon, it would be a crime not to since we are discussion fire.

:violent3:

[JohnGunn]

However let me let you know that whenever I pull off fuel lines hardly any gas comes out of the fuel lines at all. There is no spraying action at all and I may get 2 to 3 ounces at best total out of the fuel lines. More fuel comes out of the filter after I have it off than comes out of the actual fuel lines.

Thanks, Roboskittle, for this bit of information. I have only had to relieve fuel pressure once, when I replaced the fuel filter on my late departed '90 Festiva. At that time I turned off the fuel pump by disconnecting the inertia switch before starting the engine. It worked fine, but I had to remove a large plastic panel on the left side of the trunk area because I couldn't bring myself to hit the switch with enough force to trigger it in place.

When contemplating some minimally intrusive procedure, I wondered about how much fuel would actually "spray" out if one just pulled a hose from the filter. The 2 to 3 ounces you estimate sounds about right to me. So, maybe the least intrusive method would be to wrap a rag around the top filter connection and just pull off the hose. The part of the system that is under pressure is - from a check valve at the output side of the pump, through the line to the filter, the filter, the line from there to the fuel rail, and the rail itself. I guess most of the gas in that run would be in the filter.

Of course, in addition to the amount of fuel under pressure, another important consideration is the pressure in the system when the pressure is released. On my Aspire when the engine is turned off at idle the pressure should be "30-38 psi." But I wonder how efficient the system is at holding that pressure over time. The points of question are the fuel pump check valve, the injectors, and the valve in the fuel regulator. My guess is that over time the pressure will drop to zero just by allowing the car to sit idle, i.e., not starting it. But how would you know if you had waited long enough? Someone with a late model Aspire, with a valve on the rail for pressure testing, could do an experiment to answer this question. My Aspire is a '94 without that valve.

Here is a point at which the Service Manual, written for professionals working on the clock, leaves out options that we, shade-tree mechanics, have available to us. If I plan ahead I could just not use my car for a couple of days before removing the filter in hopes that the pressure would have bled down by itself in that time. Nothing much more non-intrusive than that. At this moment this seems to me the best of all possibilities, it requires no tools, not even the vacuum pump my proposed method uses. But since I proposed it, I will use it with this filter change, to satisfy my own curiosity and publish whether it can be added to the long list of methods that get the job done.

I'm glad my post found some interest. I believe some of the most helpful contributions to this site come when members with lots of experience tell what they have found to be the best way of doing something.

Thanks for all the time and effort. I'll report my results as soon as I find the time and peaceful state of mind I need to do my best work.

John Gunn
Coronado, CA

[scitzz]

A "peaceful state of mind" only requires a beer or two

[JohnGunn]

A "peaceful state of mind" only requires a beer or two

For me, for better or worse, "the road not taken." (Robert Frost)

John Gunn
Coronado, CA

[easywind]

I have my aspire in arizona and I'm in NY but if I remember correctly there is a fuse to pull which shuts off the fuel pump that relieves the pressure. A shop rag should be sufficient to hold all fuel that spills.
Gasoline will usually kill a cigarette if it's throw into a barrel with gas, it's the fumes that will explode but there is always a chance gas will catch fire. Smoking is not the brightest of moves.