Fuel level not correct even after brand new racetronix pump/sender

[Boston GN]

This is my year to get rid of all the little issues this car has.
Fuel level hasn't been right for 10 years. I usually go off of the trip. Anyway, put in brand new racetronix set up with wiring harness, the whole nine. So, that leads me to believe something in the dash that's causing the issues (Analog dash). Took out the 7mm screws and popped off the fuel level gauge, Everything looks very clean as far as the three connections go. Anything else to look at?

 

[standupjskiguy]

I have no experience with racetronics but the stock unit can be adjusted.
My guess would be there must be some adjustment on them also.
On my 85, it was off, so I cleaned the coiled wire and the wiper. I accidentally
moved the calibration screws and messed it up but I got it back to normal.
If I remember correctly, it moved the coil up and down in relation to the arc of the wiper.

 

[Chuck Leeper]

Very small resistance in the wiring will cause inaccurate readings.
Clean the connectors, check for ohm readings across the grounds.

 

[Pronto]

Any how to's on cleaning up the dash gauge connections? My Racetronix sender worked accurately for 2 months. Filled up one day and now it's off.

 

[Jerryl]

I did it the hard way. Brand new tank, RT hanger pump combo.
Set the tank at the same angle as mounted, and added 5 gal of race gas. The reading was off, so i adjusted the bend of the float arm till it read about 1/3, pumped the fuel out, and installed the tank in the car. Wish i would have build a fixture to duplicate the reading.

 

[TurboTdr3.8]

I put in brand new racetronix set up with wiring harness,I did the same thing and my gauge was off , took gauge out of dash and sanded the the terminals with sand paper and bingo it has never worked that good before . something about them terminals get a tarnish on them and does not make a good contact .This worked for me

 

[Pronto]

I'll give that a shot when I get a chance. Thanks.

 

[TurboDave]

Any how to's on cleaning up the dash gauge connections? My Racetronix sender worked accurately for 2 months. Filled up one day and now it's off.

My 87's analog gauge doesn't read as well as I'd like. Took the gauge out a few years ago to clean the contacts. There was just a little discoleration on them.
You have to do the best you can cleaning the pins with emory cloth or whatever. Getting the female connections clean aint so easy!! But they have to be cleaned also.
Even the smallest amount of resistance caused by even slight corrosion can throw off the gauge.

 

[Jerryl]

I did it the hard way. Brand new tank, RT hanger pump combo.
Set the tank at the same angle as mounted, and added 5 gal of race gas. The reading was off, so i adjusted the bend of the float arm till it read about 1/3, pumped the fuel out, and installed the tank in the car. Wish i would have build a fixture to duplicate the reading.

Just to clarify.
At 0/90 ohms the dash reading was perfect, so I concluded the contacts were good.

 

[Pronto]

How about electrical contact cleaner spray on the females?

 

[scgnx2]

I would avoid trying to clean the female terminals. You'll likely do more harm than good. Install and remove the gauge a few times into the sockets. This will clean the female plating and make for better electrical contact.

 

[Nick Micale]

After getting fed up with the stock-type pump hanger and especially the in-tank sender, we decided to fabricate a "quality" piece!

Not only did we use a much better sending unit, we have electrical bulkhead connectors instead of the crap connectors.

My street car, with dual in-tank pumps, is now accurate over the entire range within one gallon, not 3 or 4.

We can now also add AN fitting if desired of any size for the needed application.

 

[Racetronix]

This is my year to get rid of all the little issues this car has.
Fuel level hasn't been right for 10 years. I usually go off of the trip. Anyway, put in brand new racetronix set up with wiring harness, the whole nine. So, that leads me to believe something in the dash that's causing the issues (Analog dash). Took out the 7mm screws and popped off the fuel level gauge, Everything looks very clean as far as the three connections go. Anything else to look at?

Have you posted this question on our support forum? We have diagnostic info there which will help you.

 

[TurboDave]

Nick, Race. The area we're referring to here isn't an issue in the hanger but rather in the dash where the gas gauge actually plugs into the dash with those three little prongs. they tend to corrode a slight bit wreaking havoc with the system's resistance reading, causing the needle to read wrong much of the time.

 

[GNICETRY]

I replaced with new Ractronix and same thing. I cleaned the female and male connectors in dash. Got a little better but still off. Some other people had the same issue, cleaned the connectors and it worked pretty good then after about 3 tanks back to normal BS. Time to get working on my GNX dash!