Jumper11

OK I replaced my right side fuel sending unit because of the infamous fuel gage goes to zero. Found the jet pump clogged so I replaced the sending unit with one I purchased from ebay. Gage works fine however; when the gage is other than full, when starting the car the next day the gage is 1/4 lower than when I shut the car off the day before. The gage recovers after the car is running for about 10 min. (slowly) The gage performs correct after that until I shut it off and start it the next day. I parked the car with the gage reading a little above 1/4. When I started it up the next day the gage was at zero. I got the low fuel warning and check gauges light. After 10 minutes the gauge recovered as it was when I shut it off the day before. Low fuel warning gone, check gauges light gone. Car back to normal. Is there a check valve or something that's allowing the fuel to migrate back into the right tank?

Corvette Don

I use seafoam with about a half tank left, it works.

n8dogg

I wonder if the gauge/sender is accurate and there is an issue with fuel level equalizing.

Jumper11

Pulled the codes and nothing related to fuel system. I was wondering if there's a check valve in the system that would keep transferred fuel in the left tank. As for techron, I should have bought stock in that company.

bikerjim2000

I am pretty sure the gas crossover from left tank to the right is at the top so there should be no way to go back over to other side. Let it get almost empty. Full bottle of techron in the tank. The sending units try to keep both tanks at same level with the jet pump. If they do not agree like when jet is clogged and left tank is empty and right is full you get an empty indication. Slill possibly dirt on left tank sending unit or jet is re-clogged. Good luck!

hornet7

You need to read this thread on the fuel system.


http://forums.corvetteforum.com/c5-t...m-failure.html

Chicago1

Mine was the left side when it went to 0. I got tired of putting techron in. Changed the sender for 80 bucks and no issues since..

Jumper11

I'm not an expert but I've experienced the fuel gage going to zero for awhile before I changed the right fuel sensor/jet pump. The system worked as advertised. The right tank wasn't transferring fuel until the car was shut off and the right tank gravity filled the left tank until about 1/2 indicated. The jet pump was clogged. Now the gage does not drop to zero and I'm glad about that. Just wanted to know why the gage indicates 1/4 lower the day after I drive it and then recovers? I know the right tank will gravity level with the engine off. Thought there was a check valve to keep the left tank from back filling the right tank.