Gas Tank Gauge-Dont Worky

[dohc v6]

Ok guys I have a 94 z and just got done with the turbo kit. It has been two years. Anyways, I took the tank down to replace the pump and when I took it for a ride the first time I have a full reading all the time. But there is only 3 gallons of gas in the car. Now I did nto drop the unit when I took it out,I handeled it very gently. I did have to splice the new pump in. Would this cause a problem? Just wondering if maybe there is a fuse that would be bad or something. I know the stop light fuse is bad. Maybe a vacuum line? I dont want to have to take the tank down to find out it was a fuse.

[Crazy K]

having sat so long may have allowed tarnish to build up on the float reader, which creates resistance. full resistance = false full reading

. Simply fill the car and refill every... oh... 200 miles to see if the motion of the fuel in the tank makes it come to life again (has always worked for me.) if not drop the tank in 1000 miles.

 

 

[dohc v6]

Will do, thank you sir.

[EFFENDI]

mine has no worky since i got the car..... in 93

 

maybe i should drop my tank too..... specially now that it has no fuel in it

 

not according the the fuel gauge of course..... always says full...

[dohc v6]

I did fill it up,cost 44$ FOR PREMIUM. I will run it for a 1000 miles and see if it startes to work. If not I drop the tank and replace the unit.

[Andrew]

maybe i should drop my tank too..... specially now that it has no fuel in it

yes. its worlds easier when its empty already.

[Doug Goodwrench]

Fill the tank, then drop it... it falls much faster this way. lmao.

 

Sounds like the varnish build-up from sitting. (somebody already said that.)

 

I have a '93 Cutlass that works maybe 2% of the time (that 2% is when I fill up the tank. lol.), and this particular car sat for about 2 years or more.

 

It seems to be getting better the more gas I run through the tank.

 

Sea Foam is supposed to be a great product. Maybe?

[gp90se]

if it is varnish, seafoam will remove it almost on contact, I would try 1/2 a bottle with 6 gallons of fuel or so. It will also clean out the rest of the fuel system, just dont get into boost to much, i dont know what seafoam does to octane ratings

[dohc v6]

well 1200 miles and it still does not work. So is there any way to check to make sure its 100% the sending unit. I dont want to drop the tank if I dont have to.

[dohc v6]

Ok. I took the fuses out, the ECM/BATT, and it was good. I looked around the turbo and did not see any melted wires that would cause this problem. So what is my next step for diagnosis.

[dohc v6]

ok with the igniton off the gauge reads full, with the car on or ignition turned to on its past full, like I mean past full

[Andrew]

just replace the sender. they are common to go out. its a rare day that a gauge is broken.

[1990lumina]

It's also normal for the guage to read way fast full..but it should eventually start falling as the fuel is used up. My Lumina's guage goes past the F

[Crazy K]

you could use a digital multimeter at the harness connector pigtail under the car, behind the tank.

 

I don't recall which two wires, but there are only 4, and you could see it is an open circuit.

[joey b]

yeah, and check for resistance. I believe that it is 2 purple wires and I believe they are located opposite on the harness from one another. If you get an open circuit (very high resistance) and the tank is not full then the fuel tank level sensor is bad. If you do get resistance value that is not high then with the ignition in run, check for voltage coming from the engine (you may have to check both of the purple wires running to the fuel pump).

 

If the sensor is faulty you may be able to buy just the level sensor for about 130. However, if you have the money you may just want to replace the whole unit while you have the tank and pump all torn apart.

[dohc v6]

I am going to just go ahead and replace the sender. I dont know why when I put the car back together it stoped working. The only thing that I changed was the fuel pump to a walbro 255 hp. I had to cut the existing connector for the fuel pump and crimp on a new on becuase the pump connectors are different. Could that do anything. Also rockauto.com has the unit for 50 bucks where discount is 155.

[pwmin]

hmm, dont remember having to cut anything when i put a walbro in a 95 Z. could have something to do with that.

[dohc v6]

there is no fuel pump for the lumina that plugs right in. I had to buy a special connector and crimp it on.