Man I just fill the Truck up Yesterday and Ive probly drove it 50 miles and half of the tank is gone. I losing gas somewhere, were should I check I remember a thread about something being notorise for leeking but now I cant find it, And dont remember what it was that he said did it. Help please this is getting expensive fast.I have a 1998 chevy blazer I put this under the first series and its a second year series soory for the mix up damn.

 

Are you sure the gauge is working properly?
I know mine is all over the place, in fact I don't even pay it any attention anymore, just fill it up, when it hits 275 miles, I fill it up again.

Can you smell gas anywhere?

Most of the time it's the fuel pressure regulator that leaks.
Follow you're fuel lines from the throttle body backward and you'll see the FPR.

 

Man you gave me a great idea before I tear that cover off Im going to see how much gas i get to the full tank I know that the gas hands are all screwed up but this one has been a good one but I dont smell gas anywhere thats why I thought it was interenally. I keep up with my oil changes with my trip and i dont think i have two

 

Yeah, the gas gauges in 2nd gen Blazer's and S10's are a common problem.
The connections in the tank get corroded and it's all over the place.
Once mine hits half a tank it'll just drop to empty randomly, happens all the time.

My company truck is a 2001 Chevy 2500 HD, does the same thing.

 

I think your right because sometimes when I first start it up it will read more for a moment then drop down. So if I cant smell it there isn't anywhere else it could leak your saying there is no lines on the inside that could be leaking. I see where the fuel lines tie in on the top of the moter and this al seemed to start when I changed the fuel filter last week. But most inportant I see no leaks I fallowed them all the way back to the carcoil box on the back and to the tank.Everything looks farlly new.

 

Correct me if I'm wrong, but I don't think ur gona find the fpr there, I'm pretty sure its
under the intake and part of ur spider. Smell ur oil and see if it smells like gas or if its way over full on the dip stick

 

Yep, it's under the upper intake plenum.

 

What would it mean if this is the case? The oil smelling like gas or being over full!

 

The oil is gonna smell a little like gas no matter what, now if it smells strongly of gas that could be an indicator that the FPR is leaking.

But, if it was leaking the truck wouldn't run good
You can get a fuel pressure gauge from the parts store for about $40.
The fuel system has to have atleast 55PSI with the key on and cannot drop below 50PSI ten minutes after the key has been tuned off.

Perform this test and you'll know if it's the gauge or FPR.

 

just a thought but a few years ago i lived in a pretty bad nieghbourhood and was having the same problem. turns out my gas was leaking from my truck right into my nieghbours tank lol. caught him out there at 4 in the morning with a can and hose. hopefully this isnt your problem but you never know.