Fuel system problems / questions


98se5speed
01-13-2010, 10:42 PM
Well, I've been detailing my fuel system woes in another thread (my "new to forum" introduction) but I figured this deserved its own thread.

Long story short (if you want the long version, here's my previous thread (http://www.automotiveforums.com/vbulletin/showthread.php?p=6092070#post6092070)), fuel is pouring out of a small black box behind the gas tank. It's mounted up behind the bumper, and has 1 hose coming out of it going towards a mystery evap/emissions box of some sort ahead of the tank.

I just found this diagram of the fuel system. It makes no mention of the small box I found behind the tank. Or perhaps I'm not reading something right:

http://jamieanton.com/gallery/albums/misc/cars/rodeo/gas_system.jpg

Here is the box I speak of:
http://jamieanton.com/gallery/albums/misc/cars/rodeo/gas_leak.jpg

The hose coming out of that thing heads around the tank and to a box in front of it:
http://jamieanton.com/gallery/albums/misc/cars/rodeo/gas_hoses2.jpg

As far as I can tell, I definitely have my 3 tank hoses connected right (I replaced the tank with a used one not long ago, thinking it was the source of my leak):
http://jamieanton.com/gallery/albums/misc/cars/rodeo/gas_hoses3.jpg

This is the tank I replaced, it was pretty rusty/cruddy looking. Found a nice one in the yard from a TX truck:
http://jamieanton.com/gallery/albums/misc/cars/rodeo/gas_tank.jpg


SO, any ideas? I imagine the evap system is only supposed to have air in it? Since my truck is also running terribly, perhaps my fuel pressure regulator is totally effed up and dumping fuel back into the evap system?

I'll stop my theories now, thanks for ANY advice anyone can offer!!!!

2000izusu
01-14-2010, 04:03 PM
i don't know what the mystery black box is but judging by the symtoms the charcoal canister has to be filled with gas?

just a quick thought: if the fuel rail has a shraeder valve then you can borrow a fuel pressure guage from autozone and test and see if the regulator is overpressurizing the system when left off for periods of time. if you can borrow one, then you can also tape it to the windshield and go driving and see if it is underpressurizing when it sputters.

also if it has a fuel pressure regulator? and it is vacuum activated, then you can see if it has gas in the vaccum line. (which would mean broken diaphram).

hopefully other with more knowledge of the 1st gen. 3.2L will chime in.

98se5speed
01-14-2010, 04:29 PM
Thanks for the reply. My brother does have a fuel pressure gauge, and I believe there is a valve right on the fuel rail of this engine. However, I think checking the vacuum side of the pressure regulator to see if it has fuel in it, a good starting point. And I'm not driving it one foot before I think I've actually figured something out. I can't believe I haven't burst into flames driving this thing around. Best part, where it was pouring out fuel, it was dumping right onto the wires for the trailer harness. One spark coulda been interesting.

98se5speed
01-14-2010, 07:17 PM
Right now, after some reading, I'm thinking it's either a vent/purge solenoid, rollover valve, or vapor/liquid separator. Either way... diagnosing EVAP problems is totally new to me, I'm feelin' like an idiot. Not too often a car issue does this to me!

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