Need help - 996 Gas gauge problem
 

Need some help diagnosing a problem. Car is a 1999 C-2 Cabriolet with 39,900 miles. Picked it up in New Jersey, and proceded to drive to Miami. When I picked it up, the gas gage was showing half full. The dealer indicated he had just replaced the fuel sender unit, so I didn't think anything of it until I stopped for gas about 100 miles later. I could only get 4 gallons in the tank, even though it read half full. I then drove for about 300 miles. After about 250 miles, the gage did start to move downward like you would expect. I filled it up again and the gage would not move above half full.

I assume it is the sending unit, but the dealer indicates he had just replaced it prior to me picking up the car, and I trust the guy.

Any thoughts?

Thanks for helping.

Barry

I had the same problem with my car, even though mine is 20 years older than yours. It turned out that the sending unit had a tear in it and the float was not going up becuase it was getting stuck at the point of the torn outer metal. Replaced it and everything was fine. I would pull out the sending unit and inspect it if I were you.

Barry,
Call the dealer. If the fuel sender was indeed changed, the person doing the work would have noticed the fuel level by sight and seen the gauge didn't match up. This isn't rocket science.
Likely someone pulled the sender and moved the float up and down a couple times and said OK fixed.
You know better.

Guys:

You both confirmed my thoughts - but I keep trying to trust people who say they did things.

To me the sending unit is the only thing that can be causing this problem - but I've seen some strange electronic malfunctions in my years of playing wiht cars.

Thanks for your help!

Barry

Well the dealer must not have read the factory service manual under the section "Calibrating the fuel level sensor system"

It clearly states that calibration with the PST2 is necessary after replacement of the 1)fuel tank, 2) fuel level sensor or 3) instrument cluster.


Todd

Todd:

Never thought of that. I pulled the sender out of the tank to see if it looked OK and it did. What I found is the float might have gotten hung up on the fuel lines and the the wiring and the float must be facing the right direction in the tank.

Calibration is something I never thought of. The last time I changed a float in my 914-6, all I did was yank out the old one and put in the new one.

Barry