CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Fuel Gauge Issue

The fuel gauge on my 2000 Blazer is flipping from empty to full. (Even as I drive down the road it moves.) And nothing in between. The fuel pump was replaced about a year and a half ago. I’ve been told the fuel pump controls the fuel gauge. So I’m wondering if there could be a loose contection or if this is a sign the pump will go bad again.

The fuel pump assembly has a float the operates a rheostat or a variable resistor. And that’s what operates the fuel gauge. One of the things you have to watch for when installing an in-tank fuel pump is, to make sure the float of the fuel pump doesn’t hit or bang into the fuel tank opening. Because the the float circuit is very delicate and it doesn’t take much to mess it up.

If you want the gas gauge to work again, have another fuel pump assembly installed very carefully.

Tester

Thanks Tester. The gauge worked for almost a full year. Then slowly stopped working. Lucky for me, I know the vehicle well enough to know when to get gas before I run out.

BTW it involves dropping the fuel tank again. Ask the folk who did the job replaceing the pump. This on a new car should last at least 60k miles. While it is not immediately connected to their work really they were the last ones messing in the tank. Maybe they can give you a break on the fix.

The place that replaced it is nearly 4 hours from where I now live. So I’m thinking I’m out of luck there. But the vehicle is 12 years old now. The original repair was $700. Doubt it would be a break good enough to drive out and back. Plus the overnight stay…

If it were me, I’d forget the expensive repair and start relying on the odometer and knowledge of your tank capacity and approximate mpg, and just refuel every 200 mi or so.

Or, this may be the perfect opportunity for you to get a device that I’ve had my eye on but can’t quite justify purchasing. You can set the display to show the exact amount of fuel used and fuel remaining, if you reset after each fillup. And it’s a lot less expensive than a new fuel pump.

Huh, the scan gauge seems to be the trick. I went for years without a gas gauge after having the gas tank replaced in my Riviera. The part was over $300 so waited until I finally needed a pump. I just reset the odometer at each fill up and also the trip computer. I never knew what I had left but always what I used and just filled up every day anyway after mile 100+ mile commute.