00 regal fuel level

[fastmoney]

I HAVE A 00 BUICK REGAL 3.8 S.C. FIRST MY GAS HAND WOULD ALWAYS STAY ON FULL NO MATTER HOW MUCH FUEL WAS IN THE TANK. SOMETIME IT WOULD MOVE TO WHERE I THINK IT SHOULD BE BUT QUICKLY GO BACK TO FUEL AND STAY THERE. I WAS GOING TO TRY TO REPLACE THE LEVEL SENOR ON THE FUEL PUMP BUT I CAME ACROSS A REBUILT FUEL PUMP FOR JUST A FEW MORE BUCKS THEN THE SENOR ITSELF. I WAS TOLD ALL PARTS WERE NEW ON THE PUMP INCLUDING THE SENOR THEY JUST REUSED THE PLASTIC HOUSING. AFTER REPLACING THE PUMP THE GAS HAND GOES TO FULL AND THEN GOES TO EMPTY WHERE IT STAYS and light comes on. is there anything that can cause this problem other than the senor on the pump. thanks for any help.

[BNaylor]

So are the symptoms the same between the old and new-used level sensor? Hard to tell by your post since the uppercase letters are distracting. Other possibilities are wiring, PCM module or the IP Cluster gauge.

[fastmoney]

Yes the symptoms are the same as before, a little movement of the gas hand at start up. After start up gas hand goes back to full where it stays. Im going to contact the store where i bought it to make sure the senor is new. If the senor is new is there any other things i may be able to check at home.

Thanks in advance.

[BNaylor]

What happens when you disconnect the electrical connector for the level sending unit on the top of the fuel pump assembly? What does the IP fuel gauge read then? Note: The same connector supplies the 12 volts and ground to the fuel pump but not a problem for testing the level sending unit. Also, you can check the resistance of the level sending unit with a multimeter (DMM) in ohms position.

[fastmoney]

Ok I have tried removing all electric connections from the fuel pump with the same results. I tried to test the connectors with a multi-meter but i'm not sure exactly how to do this. Also when you say "The same connector supplies the 12 volts and ground to the fuel pump but not a problem for testing the level sending unit" do you mean the connector with the four wires (A,B,C,D). Is the connector to the level sending unit just sending info to the PCM and not supplying any power? I really need help . Also as a note my service engine light came on with codes PO440 evaporative emission system and PO452 Evap. emission system pressure senor/switch low input. Not sure if that is related but thats all i got for now.

[BNaylor]

That is the right connector. The other connector is to the pressure sensor for the evaporative emissions system.

If the gauge is still whacky with the right electrical connector disconnected then the problem appears to be back to the PCM and IP.

[fastmoney]

Ok just to clarify a few things I should disconnect the plug with the four wires? When i do should the fuel hand then go to empty? I do believe that the fuel hand did go to empty with the plug disconnected. Im going out to recheck the previous statements. Will repost soon.

[fastmoney]

Ok after recheck, when the sending unit is unplugged the fuel hand goes to empty in about 30 sec. once it is plugged back up the fuel hand will move to 1/2 full then to full where it stays until the sending unit is unplugged again and returns to empty.

[BNaylor]

Then the circuit loop looks good and the IP gauge is acting properly. It sounds like the level sensor is suspect. There is a static resistance check that can be performed and to see if the values from low to high float are in tolerance. I'll see if I can find the specs.

[mikepieronek]

I just put up an article on my website about replacing a fuel level sensor on my 1999 Buick Regal. The problem of the level being full matches my experience, too. If the sensor is similar to one I bought on ebay, it needs more weight on the float arm. Check out my article and scroll to the bottom to see what I did.

http://www.redhouseon7th.com/redhous...sor/index.html