Rahimatron

I have a 91 4runner. I looked up "Relieving fuel system pressure" in my Chilton's manual and was surprised at what I read. It says to wrap a clean towel around the union bolt at the fuel delivery rail and slowly loosen the bolt. Isn't this really dangerous?

I was thinking about just disconnecting the fuel pump power or removing the fuse and cranking the engine a few times. I noticed that there's an EFI relay as well as an EFI fuse. Does the relay only control the fuel pump and not the injectors?

Thanks for the help.

rimpainter.com

Yes, if you are smoking. Otherwise it will work fine.

arjan

I just replaced my engine and when I took the fuel line off, only a couple of drips came out. Nothing to worrie about in my opinion. Maybe first let the vehicle sit for a while, so most of the pressure is gone.

eric-the-red

On my '93 there is a small access panel on the floor under the rear passenger seat. If you unscrew that there is a connection for the fuel pump. Undo the connection and run the engine until it quits and the fuel pressure is relieved.

4RunnerFever

I just replaced my fuel filter and the Hayes manual suggested what you said - remove the fuel pump fuse, start the engine, and then wait till it shuts down from lack of fuel.

My motor wouldn't turn over at all without the fuse, but I cranked it a few times and figured I was good to go. No problems removing the fuel filter.

I'm no professional wrench though

Schuey2002

So,uhm.. taking off your gas cap won't relieve any pressure on the system??

WATRD

That will relieve the vacuum in the tank, but what they are talking about is after the fuel pump. The fuel pump draws from the tank, creating a vacuum and pressurizes the system from there to the fuel rails for the injectors.

When I want to bleed the system off, I let it sit for a while, then crack the banjo bolt at the end of the fuel rail. A few drops come out and the pressure is relieved.

4RunnerFever

Pretty sure he is talking about pressure in the fuel lines created by the fuel pump. When the vehicle is shut down there is still a little fuel in the lines, etc.

Does that make sense?

X-AWDriver

I'd do the fuel pump fuse method;simplest and safest and can be performed while smoking.

lee

why must one do this? forgive my ignorance

eric-the-red

If you undo a fuel line when it's pressurized fuel sprays out, especially with fuel injection where the pressure is about 30-40 psi. It's pretty much guaranteed that the fuel will end up in your mouth. It's even more fun when you're working on diesels.