How do i depressureized the system, and do i need to put pipe dope on the threads

 

Pull the fuse for the feul pump and start it, car will run for a bit and just let it die then restart till it wont anymore! Worked for me but feul stil leaked on me but no pressure. I did not put anything on the threads and it doesnt leak, been a few months since i did it.

 

i cant find a fuel pump fuse, onlyu inj 1 inj 2?

 

i'd bleed the pressure at the fuel pressure test valve, and remove the gas cap. or i think you can just wait a couple hours and the pressure will drop on it's own.

 

According to the GM manual I have for my 88 Camaro it says to pull the inj1 and inj2 fuses which will cut off power to the injectors. Then try to start the car and of course it will not run. Then try it once again for about 3 seconds. When removing the filter it will leak but it will not spray as it would if pressurized. And be prepared for a lot of gas fumes, it gets lovely if you don't get some fresh air so keep the air circulating.

 

i pulled the inj 1 and inj 2 fuses and it wouldnt start but did not depressureize, i undid the gas cap and that took care of most of the pressure.

 

You don't need any teflon tape for the threads. When you remove the old filter, inspect the ends of the fuel lines. There should be a small o-ring at the extreme ends of the tubes. Sometimes an o-ring can stick inside a fuel filter and come off the tube! As long as those o-rings are there, you won't get any leaks.

I've never depressurized my system; just wear goggles and do the work outside. I also put my arm thru a garbage bag so I don't get any gasoline burns. Avoid dropping a wrench onto the concrete; it can cause a spark (and explosion)!

 

Tom how do you put up with the nice gas fumes from the extra spraying gas? I changed my filter yesterday and I think I lost a few brain cells, I just left the garage as soon as I could to let it all fall out on the floor.

 

I actually do the filter outside... didn't want to blow up the garage!

And never set up an electric fan in the garage, either- the brushes from the fan motor could cause a spark and BOOM! An unhappy ending.

 

I may be wrong but the only place you should find pressure is after the fuel presser regulator. So really just the fuel rails n such.
The pump would need to run 2 7 as I see no way it can / could hold pressure. I am not aware of any one way valves in the feed line. Opening the gas cap just lets air in tank. not really gonna help. as that little bit of vacuum can help hold the fuel in, instead of while you are changing the fuel filter, the open line creates a siphon cause of the lack of vacuum in the tank and gas runs all over the place.

Think most of that is right.

 

Is there a reason the fuel filter flows in one direction and not the other? I know if you put it in the wrong direction fuel would never get to the engine but just curious if there was a reason for that.

 

Actually, that's the only place you WONT find pressure. The only thing after the regulator is the return line.

There is a check valve inside the fuel pump. That is how the entire feed line stays pressurized.

BTW, I rarely depressurize a fuel system to replace the fuel filter. Not worth the time. Just crack the lines loose, then wrap a rag around it to absorb the fuel, slap the new one in and I'm done.

 

My guess is that the filter's more efficient one way as opposed to the other way; other than that, I don't know. One day I'll have to cut open a fuel filter

 

lol alright Tom.

 

Some time the filters are cone shaped. The out side has more surface area. Like a clear brass slag cone motorcycle filtered.
Gas comes at the top of the cone, through and out.

 

LOL! Hey I like Gumby's answer. Now I don't have to cut open a filter.