Just bought a 94 Z28. I bought it from a guy who lives about 2 hours away. Before leaving I filled the car up, I put 20 bucks in it. Drove the 2 hour drive home and noticed the gas gauge barely dropped, maybe to 3/4th a tank. And I know an lt1 drivin that far does not get that great of gas mileage. So I get it home and drive it some more on the same tank of gas. The fuel gauge was just under half a tank when, while driving, the car just lost all power. Steering wheel locked up and wouldn't start. Waited about 5 min and it started back up and I drove it to a nearby gas station and put 10 bucks in. The gauge moves up when I put gas in it and does go down, but I don't think it's accurate. I texted the previous owner and he said it has a aftermarket fuel pump in it. Also no gas light came on. So is it the gauge or fuel pump?

 

sounds like whoever installed the new pump bent the level sender or got something in the way so as not to let the fuel level float drop all the way. that said the gauges on the 4th gen are kinda stuck in the 70s, lol, the tank is thinner at one end and is set on end at an angle soooo, as the fuel level drops the tank gets thinner and drops faster. this means when you have 3/4 tank you have a little less than half,,,, well in your case i would say at 3/4 you must be about 1/4. anyways your issue is normal to a point but not. my first 4th gen ran out just above 1/8 tank. this one goes just to e and runs out. it does sound like your getting poor mpg. stock running right lt1 should be getting at least 25 on highway, im getting 18 to 21 with 3.7 to 1 rear gear ratio and motor built to 400hp. look here and post if you like https://camaroforums.com/forum/lt1-l...uta-gas-69608/

 

That shape of the tank throwing the reading off explanation never makes sense to me, and it probably never will, for good reason. If a sending unit that's designed for a perfectly square symmetrical tank were thrown in there, then yes the 3/4, 1/2, 1/4 points would be off. But the sending unit in this car is designed around the shape of the tank. If it's off, it's bad. I've had a couple of 4th gen's, and neither one acted out of the ordinary. It does take a while for a full tank to start to drop off of full, but every car I've ever had acts this way.

 

15 gal tank, 1/2 should =7.5 gal, neither of my 93s took 7.5 gal when at 1/2. more like 11 gallons. yes the level of the float in the tank may be 1/2 way up the tank but the tank is not half full.

 

That just means your sending unit is whack. With the tank being slightly narrower at the bottom, the float would be past the physical half way point (vertically) to read 1/2 tank. Not that you'd be able to see, unless you had a clear tank.

 

right the factory setup is fail. i dont think the arm is long enough or shaped right to reach the top. when its up it takes a good drop for the angle to effect the sensor so its full for a long time.

 

So will a new sending unit fix the problem? I was told this is an expensive fix and should be done at a GM dealer. I guess until then if I have half a tank I really have 1/4 and need to fill up, right? 3/4 = half, full=3/4 and way past full= full

 

i think the arm got bent. also yes a fuel pump or fuel pump sending unit is going cost in the 800 dollar range if done by a shop. now if you do a hatch mod to do pump or if its already been done then you can change it yourself without to much anger. brb

 

ok im back, go here and click the link at number 9. other info here as well. https://camaroforums.com/forum/93-02...62/#post557634

 

If it was my car, I would save my money and learn to just compensate for the difference in accuracy.