Fuel Gage Isn't Correct

[NorwegianViking]

Ran out of gas thinking that I had plenty of fuel. :eyerole This has actually happened twice now. All bars are showing, but the tank is not full. I know I can take it to the shop, but is there an easy fix for correcting the fuel gage reading so that it shows the right amount of gas in the car? Thanks for your help.

 

[Rogue]

I'm thinking it's your fuel tank sender unit that is malfunctioning.

Did you actually check to see if you had no more fuel in the tank? I'm thinking if you actually had no fuel but the gauge was reading half full or something, you have a faulty sender.

My daughter's Saturn L300 (Opel Vectra based vehicle) has the opposite problem. Fuel gauge read low but it actually had a quarter tank more. Faulty sender....needed to drop the fuel tank, replace the sender assembly. The assembly was sold only through GM and cost US$300. Ouch!

 

[vetteoz]

I know I can take it to the shop, but is there an easy fix for correcting the fuel gage reading.

Might help
Fuel Gauge Sending Unit Repair Tech Article. - Corvette Forum

 

[gmjunkie]

First thing I'd do is change the fuel filter and dump a couple 20 oz bottles of Chevron TECHRON Concentrate Plus in a full tank of fuel,drive it enough to mix it good and let it set a day or so!! Then start driving it,if the gauge hasn't started working by the time that tank is empty add another bottle and fill it up and run it some more!! If the gauge isn't working by the end of the second tank,sending unit will probly have to be replaced!!
If your gauge starts working,drop a bottle in about every 2-3,000 miles after that!
Allot of GM vehicles have this problem with the gauge,Not just Corvette!!

This has worked for me more than 95%, Corvette,Full Size Pick Up,Tahoe,Blazer,S10!!

 

[aklim]

Never tried this but I think it might work. Take out pump/sender unit. Put the car in run position and see if the gauge changes readings when you move the float.

 

[ßill]

Had a similar problem. It turned out to be the float arm was getting hung up on one of the hose clamps between the pump and the flange at the top of the tank. Solution, rotate the clamp.

 

[TWISTERUP]

First thing I'd do is change the fuel filter and dump a couple 20 oz bottles of Chevron TECHRON Concentrate Plus in a full tank of fuel,drive it enough to mix it good and let it set a day or so!! Then start driving it,if the gauge hasn't started working by the time that tank is empty add another bottle and fill it up and run it some more!! If the gauge isn't working by the end of the second tank,sending unit will probly have to be replaced!!
If your gauge starts working,drop a bottle in about every 2-3,000 miles after that!
Allot of GM vehicles have this problem with the gauge,Not just Corvette!!

This has worked for me more than 95%, Corvette,Full Size Pick Up,Tahoe,Blazer,S10!!

I agree--I've fixed similar problems with my wifes Buick Regal and our GMC pickup using the above Techron product---sure worth a try.

 

[aklim]

Just take the fuel sender out and test it first. Could be that you might have to spray it with brake cleaner or whatever.

 

[93Rubie]

First thing I'd do is change the fuel filter and dump a couple 20 oz bottles of Chevron TECHRON Concentrate Plus in a full tank of fuel,drive it enough to mix it good and let it set a day or so!! Then start driving it,if the gauge hasn't started working by the time that tank is empty add another bottle and fill it up and run it some more!! If the gauge isn't working by the end of the second tank,sending unit will probly have to be replaced!!
If your gauge starts working,drop a bottle in about every 2-3,000 miles after that!
Allot of GM vehicles have this problem with the gauge,Not just Corvette!!

This has worked for me more than 95%, Corvette,Full Size Pick Up,Tahoe,Blazer,S10!!

I will second that, my Ruby when I bought it was doing that. So Chevron Techron it was. Ford used to use that stuff too, last I heard this problem is caused by the sulfur in the fuel reacting with the sweeper arm of the sending unit. All I know is the Chevron Techron is good stuff, it is ALL I use in all my cars. I think it is GM's official fuel system treatment/fuel injector cleaner???

 

[NorwegianViking]

I'm thinking it's your fuel tank sender unit that is malfunctioning.

Did you actually check to see if you had no more fuel in the tank? I'm thinking if you actually had no fuel but the gauge was reading half full or something, you have a faulty sender.

My daughter's Saturn L300 (Opel Vectra based vehicle) has the opposite problem. Fuel gauge read low but it actually had a quarter tank more. Faulty sender....needed to drop the fuel tank, replace the sender assembly. The assembly was sold only through GM and cost US$300. Ouch!

Thank you for sharing with me the possibility that the fuel tank sender unit might be malfunctioning. I have been filling up the tank and watching the trip odometer. The tank always shows full, even when the tank is half.

I wish you luck on your daughter's Saturn. Times like these $300 is a lot of money to have to fork over. Best wishes and I appreciate your post. Thanks again.

 

[NorwegianViking]

Might help
Fuel Gauge Sending Unit Repair Tech Article. - Corvette Forum

Wow! That's a great article. I really appreciate the pictures too. I noticed something about the fuses too. I will check them out also. Thanks for the link!

 

[NorwegianViking]

First thing I'd do is change the fuel filter and dump a couple 20 oz bottles of Chevron TECHRON Concentrate Plus in a full tank of fuel,drive it enough to mix it good and let it set a day or so!! Then start driving it,if the gauge hasn't started working by the time that tank is empty add another bottle and fill it up and run it some more!! If the gauge isn't working by the end of the second tank,sending unit will probly have to be replaced!!
If your gauge starts working,drop a bottle in about every 2-3,000 miles after that!
Allot of GM vehicles have this problem with the gauge,Not just Corvette!!

This has worked for me more than 95%, Corvette,Full Size Pick Up,Tahoe,Blazer,S10!!

Awesome. I will get some tomorrow and try it. Sounds like a really good idea. I appreciate your help!

 

[NorwegianViking]

Never tried this but I think it might work. Take out pump/sender unit. Put the car in run position and see if the gauge changes readings when you move the float.

Thanks for the idea. I am really not a handi-person, so I don't know if I will tackle that myself, but one day maybe I will build up enough courage. Appreciate the technique.

 

[NorwegianViking]

Had a similar problem. It turned out to be the float arm was getting hung up on one of the hose clamps between the pump and the flange at the top of the tank. Solution, rotate the clamp.

Thanks for the help. I will see if I can do this. Sorry that you had the same problem. It really is the pits to run out of gas......it is one of my nightmares. Hope it never happens to you again.

 

[NorwegianViking]

I agree--I've fixed similar problems with my wifes Buick Regal and our GMC pickup using the above Techron product---sure worth a try.

Thanks for the reassurance that the Techron Concentrate Plus would be a good thing. Sounds like the easiest and most cost effective fix! I appreciate your verifying what gmjunkie said!

 

[T.M.808]

BG44K is a much better product than techron,more expensive,the honolulu chevy dealer uses this product instead of their own GM top end cleaner. This product used to keep my c5 fuel issues at bay. To much sulfer in the fuel now days.

But,has your fuel pump been changed recently? Maybe the float was bent when the sending unit was reinstalled.I just changed my fuel pump about a week ago. Took a whole 30 mins,but if one is not careful,the float can be damaged.

 

[aklim]

BG44K is a much better product than techron,more expensive,the honolulu chevy dealer uses this product instead of their own GM top end cleaner.

This product used to keep my c5 fuel issues at bay. To much sulfer in the fuel now days.

IIRC, someone said that the BG salespeople give spiffs and what not for the use of their product

Got a link on sulfur and the problems? It might affect catalytic converters but how does it really affect gasoline injectors?

 

[NorwegianViking]

BG44K is a much better product than techron,more expensive,the honolulu chevy dealer uses this product instead of their own GM top end cleaner. This product used to keep my c5 fuel issues at bay. To much sulfer in the fuel now days.

But,has your fuel pump been changed recently? Maybe the float was bent when the sending unit was reinstalled.I just changed my fuel pump about a week ago. Took a whole 30 mins,but if one is not careful,the float can be damaged.

Thanks for the tip on BG44K....I will look for it at the auto supply company. I hope that the fuel additives will fix the problem. I don't have the confidence to tackle taking the fuel pump out, but I will put it on the possibility list. I appreciate your insight.

Wow...c5....lucky you! I hope it gives you many more miles of pleasure. Sounds like a great car!

 

[aklim]

Thanks for the tip on BG44K....I will look for it at the auto supply company. I hope that the fuel additives will fix the problem. I don't have the confidence to tackle taking the fuel pump out, but I will put it on the possibility list. I appreciate your insight.

Wow...c5....lucky you! I hope it gives you many more miles of pleasure. Sounds like a great car!

http://www.racetronix.com/product/RX-C4x-FPA/C44-PIK.jpg is where the parts are.

 

[NorwegianViking]

Had a similar problem. It turned out to be the float arm was getting hung up on one of the hose clamps between the pump and the flange at the top of the tank. Solution, rotate the clamp.

That's a terrific picture of your black vet with the black jet(?) in the background. Awesome!