97 4x4- can't put gas in truck

[wjburken]

thanks for replies
truck is a 97 tahoe.
today- friday- i am just over 100 miles since last attempt = not out of gas yet. not sure at this point if i should try and put 20 in. as i have run out twice since having the truck and in my life- this truck- needle did not move at all. maybe i got lucky the 2 times i did fill the truck up.
as for the post on how to check - dont mean to sound like an idiot. but i dont have a clue where to start - what to look for- where to go with a tester i barely know how to operate. sorry- just being honest. guess when i googled it a while back, first thing i saw was - some plastic part in tank breaks, and im not really trying to drop the tank. so been going with 20=100 miles. when i filled. the 80+ got me 400- so thats how i been riding the last year plus-
thanks again for the replies

rear of truck leaks water inside when it rains??? not sure if the right place.... but since you guys seem helpful...id like to stop that. didn't know when i picked the truck up- but first car wash after purchase... raining in the back of the truck

First off, stop measuring gas in total $ put in. Measure it by gallons.

If I read correctly, you have a 30 gallon tank. If gas was $3.00/gal when you did your $80=400 miles, $80 would give you just under 27 gallons of gas, which is almost a full tank and if you drove 400 miles, that would be between around 15 mpg which seems reasonable for your vintage of truck. With that math, if you have currently driven 100 miles, I would expect you should be able to put in between 6 & 7 gallons which at $2.00/gal would be $12-$14 dollars.

If you are able to put that much gas in, gallons, not dollars, your tank is probably venting fine and you just need to focus on getting the gas gauge working. If you can only put in 2 or 3 gallons, then you have both a gauge issue and a venting issue.

If you’re not comfortable trying to fix it, that’s fine. At least you have an idea of what to tell a mechanic and what to expect them to say needs to be fixed.

As for your leak, I think you might get more help if you post your question in the exterior section for your vintage vehicle.

 

[Big Mama]

Or just add more detail about the leak. As for the gauge look at it this way. The amount of stress and worry over running out of gas isn’t worth the price to fix it. Sounds like you’ll have this rig a while so at least take it in and get an estimate. You’ll be glad when it’s fixed.

 

[liquify33]

Here’s my .02 for free
The gauges on the dash are junk and fail. There are many videos and threads on the dancing fuel gauge. They are available on eBay for about $60, no special tools or skill needed, *IF* that’s the culprit (most likely IMO).

If you get or have an OBD-2 reader it will show voltage from the tank level sensor, which some 3rd party apps will show as a %.
BAFX scanner ($25ish)and a $10 app way more fun than dropping a 30 gal tank on a hunch.

 

[iamdub]

I think you just have a full tank of gas. With the price of gas dropping, you're getting more gas for that $20. You get X gallons for your $20 at one stop. Then, 100 miles later, that next $20 worth yields X gallons but you didn't burn off the amount put in from your previous $20 worth. Then the next one yields even more since the price is cheaper per gallon, then the next yields more since the price dropped more, etc. Eventually, you'll fill the tank and it won't take even the $20 worth of gas.

Other than fixing the fuel gauge, you could track it by knowing your actual MPG. No, not "fuel mileage" by figuring "Well, I can put $20 in and go from my house to my buddy Rayray's house, then to Walmart, then to the liquor store, then back to my house after visiting my boy up at the rim shop, so it gets pretty good mileage".

Fill it up (like it is now), reset the trip odometer, drive for about 200 miles, then fill up again. See how many gallons it took to fill it up. Divide the mileage on your trip odometer (~200ish) by how many gallons it took to fill it. This will be your actual MPG. Find out the size of your tank, multiply that by your MPG and you'll know how far you can go on a full tank of gas. If all is running well and you don't drive like a madman, you should get at least 300 miles to the tank. So then you won't have to add $20 every 100 miles. From a full tank, you can drive for as long as you want as long as it's under that 300 miles or so or whatever it ends up being and add gas accordingly.



Or just fix the damned gauge. lol

 

[exp500]

If you want to try to fix it, you're gonna have to climb underneath the tank and look for the wires coming from the puel pump/sender assy. Unplug connector, pull it down where you can see it good- maybe take a pic or 3. Look for a purple wire at the plug. Hook up your multimeter on ohms, being careful not to bend pins or stretch out female connector( I've used straight pins like for sewing) Connect ohmeter black lead to a good ground.( might need some alligator clips on a wire too.)This will show you if wire going to guage is shorted to ground, or gauge in dash is shorted. Next, connect 90 Ohm resistor inline on red lead( or 9 -10 ohm resistors in series). Set meter to dc volts, connect power12v+ to black lead on meter. Now look at gas guage. You can even use your test light as power source if you can get the ohms to 90.(light bulb has resistance too. )Hope that explains the test procedure enough for you to try it. I'm sure someone else will chime in with more help or suggestions if you need it.

 

[Big Mama]

Once you do your first DIY testing and/or repair (not saying it needs to be this one) it’ll all start to make sense. We were all unsure in the beginning. If this one’s too much do the next one.

 

[alpinecrick]

On our dive boats we used sticks to verify how much fuel was on board!

That's what I was going to suggest. Take the engine or trans dipstick, WIPE IT OFF THOROUGHLY, and slide it past the filler hose and into the tank.

 

[jroman]

thanks all for replying.
im at about 125- and plan to keep driving - hopefully i get to or close to 400 and ill know it was full. daily drives are work-14 miles- liquor store- home.
went a week without needing gas but yes, liquor store. going to ride it out and see what happens. think 30 gallon. but thats a guess.
guess maybe tomorrow i iwil try and find that wire and see if i can figure something out. though i have a feeling its not a dash issue, no bouncing. just pinned inch pass full

 

[Big Mama]

Not sure if anyone asked if you checked the fuse??? On your rig it may supply power to other things but just wondering.

 

[jroman]

didn't check.
not sure where it is.
funny- talking to a woman at work- first thing she said was check fuse....