Gas tank fuel pump leak
 

https://cimg9.ibsrv.net/gimg/dodgefo...557b4bb92e.jpg
(I pulled this picture from another post while doing a search.)

I've got a 96 Ram 1500 4x4 with the 5.2 engine with about 220,000 miles. I dropped the tank and replaced the fuel pump years ago. Replacing it is a PIA, but doable. And I'll get either a Delphi or Denso pump (Delphi is $30 cheaper on Rock Auto). I won't get the cheapest one (forget what I put in it years ago - but I was poorer then).

Anyways, mine seems to be leaking where it is circled on the picture - was dripping down the gas tank the other day. That circled piece is like it is a cork that comes loose - never happened before (and I was living in HOT states like GA and NC). Now I'm in WA. I can reach up there from the driver's side and twist it and unseat it (till it hits the underside of the truck bed) very easily.

I did a search (that's where I got the picture), but didn't get a definite cause for the leak. Is the pump just bad where it has lost a good seal where this circled thing attaches to the pump (it is like a friction fit)? If I'm dropping the tank, I'm putting in a new pump assembly, but is there anything else I should be looking at?

When I filled the tank, pulling the gas cap released a bit of pressure from the tank, so why is it pressurizing? Is it related (would make sense if it keeps "popping the cork")?

While I'm on the Rock Auto website (and my MPG averages 11.5 +/- 1 MPG) I'll go ahead and order a replacement IAC, MAP sensor, and a TPS (they're all original from 1996). I'll also get a brass cap and rotor, and a coil. Seems like I replaced the O2 sensors not too long ago. Anything else to get when I go to start putting things in my cart?

Thanks.

The vapor system isn't working check the lines for raw fuel

What part usually goes bad in the vapor system on our trucks? The Purge Solenoid Valve? Canister? Sometimes it makes more sense to me to take a gamble and spend a few bucks to just go ahead and replace a part in question vs. spending even more money (and time) for a shop to actually test the part. And both these parts are 1996 factory issue.

Circled part is filter/pressure regulator...... Where is it leaking from? Around the base, where it seals to the module? Or where the line connects?

It seems to be leaking around the base where it seals to the module. It seems like it (the part I circled) is just a rubber plug that can get unplugged. When I was feeling up there the first time it happened, the lines seemed dry.

I believe that some pressure on the gas cap is normal and good. If it has a leak you can get the small evaporation leak code. (even if your gas cap leaks) This is an emissions thing since evaporating gas is bad for the environment.

The fuel pressure regulator is what went bad on my truck. (the circled part) I replaced the entire fuel sending unit with a cheap one from Rock Auto. Now the fuel gauge is off. It will actually start sputtering with 1/8 of a tank left and the low fuel light never comes on. I bought one that was for 2 different fuel tank sizes. (you adjust it when you put it in) I shouldn't have done that. I think buying a quality one is worth it. I may replace mine again.

Question: When you let it sit, does it take a while before it will start? (and does it start right away when it has been running I guess) That is how I knew my fuel pressure regulator was bad. It would slowly leak the longer the truck sat without running.

As a workaround to avoid overheating the starter motor, I would just cycle the key to on and wait until the pump was done running about 3 times before I tried to start it. (this is to let the pump run 3 times to build up the fuel pressure)

I suppose if it is leaking on the bottom of the regulator you may not have that issue.

Probably have to replace the the pump module....... You could try pulling it out, and seeing there is anything else you can do......

Pulling the bed off isn't too bad if you have about 4 guys to lift. (I'm not sure if you did this already or not) You might have more information doing this than dropping the tank. I'm not sure which is easier. (you don't need 4 guys for 10 minutes if you drop the tank I guess)

To remove the bed:

Remove the tailgate. Remove the spare. Remove the fuel cap and the 3 or 4 screws holding the fuel filler neck to the bed. There is a bunch of wiring for the taillights, license plate lights and possibly the towing wiring. (this may vary) There is a grounding strap to the cab if it isn't already broken and a breather for the rear differential that you need to worry about. Then its just 6 bolts. It is good to have one person just checking for anything that is still connected when you lift if up with a flashlight. This list should be pretty complete though. Oh yeah, remove mudflaps if you have them or you won't be able to sit it down without ruining them.

You can run it and see what is going on that way. (no need to drop the tank) Its fun to drive it that way as well. (though you have no tail lights) The loss of that weight makes a big difference and you can do burnouts if you don't like your tires. I should have rust proofed mine when the bed was off. Also if you get the ABS/Brake lights, it is a good time to change that sensor and the wire to it. The fuel filler neck is easy to change in the process. (if it is rusty or the inside liner is going bad) There are filler necks that work with the stock gas cap. My filler neck was rusty and damaged where the cap fit on and didn't make a good seal. Since you have pressure releasing I doubt you have this issue. (maybe just some rubber build up from the o-ring on the cap)

The pop the cork theory really shouldn't do anything for the pressure in the gas cap. The fuel pressure regulator keeps pressure in the lines to the fuel rail. (the other side that is pressurized) Both sides have pressure. The fuel rail side has much higher pressure. (at least I can't think of how they are related)

You asked about other parts to order from Rock Auto:
1) Mopar PCV Valve (you have to use the global search to find it) 5175352AA $6.22 as of today
2) NTK precat O2 sensor. I had replaced mine with Bosch but 2Bit suggestion NTK 23151. It made my idle smoother $28.79 today
3) Dorman vacuum checkvalve part number 47170 (under $3 and prevents the wacky wild vents issue)
4) Autolight 3923 spark plugs. I haven't tried them myself but I have read lots of people liking them on this forum. (cheap like $2 a piece)

I replaced the IAC it helped my idle quite a bit. (standard motor products IAC) It now idles at 600 RPMs. If it is idling higher (after its warm) this may help. I don't know about TPS and MAP. I haven't done them but I would like to. They both may help fuel economy. (along with the O2 sensor) Let me know if changing those helps you. Also let me know what brand you use please. I may do both of those as well.

https://cimg0.ibsrv.net/gimg/dodgefo...9acb557dbf.jpg
So this was interesting. I drove the truck today; gas is just dripping madly from the top of the tank. So I decided to trace back from the vapor canister to the purge valve. There are two hoses going from the canister that go to the engine (a larger diameter hose #1, and a smaller diameter hose #2 as labeled in the picture) near the steering column. Hose #2 seems to go to the purge valve up by the air cleaner just fine, but hose #1 looks like it was just broke off! I don't see a corresponding broken hose anywhere, and it doesn't seem like I have a huge vacuum leak. So what connects to this hose? Some sort of vent that's open to air? I'm going to start googling diagrams (my manual isn't helpful). Any info (or a picture!) would be appreciated.

I wonder if this is related to my fuel pump leaking, or just a secondary finding.

It runs and starts fine on the first try. Starts right up when cold, and starts and runs just fine when warm. No "Check Engine" lights.

Edit: No luck with googling trying to find what that hose goes to, or if anyone sells some sort of vent or filter that attaches to the end of that broken-off hose.

https://cimg1.ibsrv.net/gimg/dodgefo...0c8fd0417a.jpg

Here you can see where it looks like something was ripped off. You can see the striations or ridges inside the end of the hose where something was making contact.
https://cimg4.ibsrv.net/gimg/dodgefo...c36c8e56ee.jpg

Here is the mushroom piece I pulled (along with a section of the hose it was attached to). You can see the ribs where it goes into the hose.
https://cimg8.ibsrv.net/gimg/dodgefo...f4b3bb4034.jpg

Here's the mushroom piece, the hose piece I pulled from my truck, and the hose I pulled along with the mushroom piece.
https://cimg3.ibsrv.net/gimg/dodgefo...4eb8197beb.jpg
And here it is attached to the hose that goes to the vapor canister. It sits up higher now, and away from the steering column.

I was striking out on-line trying to find out what went at the end of the hose from the vapor canister. All I found was a black-and-white line drawing of a Mopar fuel and vacuum line combo that may or may-not have been for my actual truck, and it looked like a mushroom thingy on the end of the vacuum line. So I went to the not-so-local Pick-n-Pull to see if I could find anything on any Gen II trucks.

Pretty slim pickings for Gen II trucks at the yard, and nothing from a Gen II truck. But looking at a couple Dakotas I saw a little mushroom thingy up by their throttle body. So I pulled the hose and cut it. It looks like that's the piece that goes on there. I'm thinking somewhere down the line on my truck it must have got caught in the steering column and got ripped off. Since it is basically an open vent, it wouldn't generate a check engine light if it were missing since it is already open to air essentially.

Now that that mystery is solved, on to ordering a bunch of parts from Rock Auto.