Hey guys, I have been having problems with my gas tanks. My front tank shows past full at all times, and my rear tank shows 1/4 tanks at all times. On top of that, I believe my rear tank is filling my front tank. I filled my front tank thinking that I had a stuck float or something (i know now that was wrong), so I was burning that up before I dropped the tank. I put some gas in the rear tank so that whenever she started to sputter I could switch to the back tank. Well today I got stranded with both tanks empty (this is how I learned that my rear tank always shows 1/4 tank).

I know that my dual valve\resovior (on the frame) is having problems, so I was going to take that out and clean\replace o-rings if I can. If I can't, then I'll have to replace it. The truck has had an issue for a long time where the fuel in the line will drain back into the tank so the fuel pumps have to prime the lines everytime I start it so I have to wait for the relays to click over before I start it. This was annoying, espcially for my remote start. I think this can be contributed to the bad o-rings too, right?

I was wondering if anyone had any input on this, if there is something I'm missing that could cause all of this to happen (fuel gauge\gas pumping from one tank to the other), or if it's 2 seperate issues (o-rings\valves being one and ???? for the other?).

 

It's the valve that switches from one tank to the other, I'd bet the farm on it. Don't know if it's rebuildable. Haynes has a test procedure, check that out first.

 

Will do, do you think that would cause the gauge problems as well?

 

Not sure on that one, probably not.

 

Yea, i can't see how it would, but I've been wrong before lol. The truck sat for about 7 months and started doing this. Had another problem with it running really rough, but I replaced the distributor and all is well with that. I'm looking up how to test that selector valve now, I'm sure its the problem, it's got so many of the tell-tale signs, but I'll check it just to be sure.

 

Read these captions:



No, the reservoir doesn't affect the gauge, or vice versa. Read this caption:

That's a classic symptom of a failing EEC. If the FP relay stays on for more than ~2sec, then there's a problem with the EEC - not the fuel in the lines.

 

You have the right guy helping you now---just do everything Steve tells ya, he's sharp!

 

I believe there was a recall on this awhile back...that valve between the tanks would fail

 

the pumps aren't on for any longer than a few seconds, a few friends of mine have these types of truck and it's on the same amount of time. I figured it would be 2 seperate issues, but I just wanted to make sure. Has anyone ever successfully reapared a selector valve like these? I've seen a few mixed reports across the net.

Edit: Thanks so much Steve for those links, they will help a LOT, I'm getting ready to start the job now

 

Sigh, so my friend came over and I wanted to show him the remote start and also flip the intertia switch so the fuel lines would depressurize. Just to check, I switched to the rear tank, and it continues to run, for 10 min before I shut it off. This is very puzzling to me because I was under the impression it was dry (I ran out of gas...put gas in the front tank and it ran fine...). This changes things because maybe the gauge is working fine for the rear tank, but for some reason the selector valve isn't switching over to the rear tank? Should I still pull and clean the selector valves?

 

I wonder if I'm just having a problem with my switch on the dash. I mean it the only common denominator here, the sending units pass thorugh it (gauge problems?), and it selects which pump turns on and when it turns on. I wasn't able to track my mileage when I filled the front tank because of the bad distributor (drove it for about 100 miles that way not knowing that was the problem), so it was running really horrible and getting bad MPG, but I can't tell how bad because it's fixed now. So truthfully, I can't tell if my rear tank is empty or not, I get under the truck and hit the tank and it sounds hollow, but so does the front tank, and I know it has gas in it. I do know that when I ran out of gas, regardless of what tank I switched to it didn't run, until I put gas in the front tank (didn't put gas in\try the rear tank). Now, it runs on either tank I switch it to, so I'm thinking that either the selector valve or that switch is bad. Thoughts?

 

It would only take a few minutes under the truck with a meter to find out if the fuel level sender is working. Read the 2nd diagram & its caption in post #6.

 

Will do, I already somewhere that I can actually test it from the fuel switch on the dash, is this correct? I have to replace my headlight switch and it's right there too, lol.

 

Yes, you can test the fuel level circuits from the dash switch, but if the fault is between the switch & the tank, you won't know until you crawl under & recheck.

 

Cool, I'll check it out a let you know the results.