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gauges not correct

TTA 1077

Well-Known Member
Anyone know what the problem might be. I noticed on the T/A nats trip that my speedo was reading 4mph high and my gas gauge was reading almost a 1/4 lower than what I had in the tank. Example, when it read a 1/4 tank left and I filled it, it only took 8.9 gallons, which I think is just shy of 1/2 tank. At the red hash marks i still had 4 gallons left. What's up with this? Running tock tire size. DontKnow:
 
I think it's those 'tock' tires!! lol

Have they always worked accurately before that you can tell? One gauge would be reasonable but two at the same time to go bad? Is there some sort of computer that works 'in front' of both of the gauges that would impact them or they just the plain ole' mechanical ones?
 
FWIW...and not much...my TTA and 92 T/A both have inaccurate gas gauge and coolant temp gauges. Speedos are both close but not something I'd go to court over.

I put a new sender in the 92 when I had the tank down and it still reads low just like yours.

...
 
Almost every Firebird/TA I've ever owned has always taken "forever" to come down off of full, but once it's under 3/8 to 1/4, it seems like a garden hose emptying the gas tank.

Just my .02 cents
 
It seems to be somewhat of a new problem, at least that I've noticed. I have my scanmaster just below the ledge mounted under the dash. gauges are stock 20 years old. The only way i found out about the speedo was comparing it to the scanmaster reading, and the fuel gauge seems to be more inaccurate than it ever was, 1/4 tank is a big differance! My steeing wheel controls crapped the bead about two years ago, could this all be related? It's a pain in the ass to try and trace electrical issues.
 
I have to wonder about the Scanmaster's MPH readings... I had my speedometer calibrated not long ago, and it was tested to be 1/4th of an MPH off. Yet, my Scanmaster will read a difference of a few MPH.
 
My speedo also reads about 3 - 4 MPH less than my scanmaster ... my Garmin gps also shows speed and its spot on to what the scanmaster shows so my gauge is defenitly off (low).
 
Factory guages traditionally suck, and the worst are the fuel guage and the temperature. The GN's don't even have an OP guage ! So, that's the 1st thing U do there. Then the next thing on both of them is the T gauge, as Ur lucky if it's accurate within 20°F. It's really just meant to be a general indicator, I think. But when U race, U want to know within, say 5°F. I'm a bit of a guage freak - I had 10 guages on one of my hot rods.

It used to be that U needed mechanical guages rather than senders to get any accuracy, but the senders have improved a bit. I always look for a 270° sweep on guages I put in. Another one of the new ones I like is an ExGasT. If Ur pushing the envelope U definitely want one. I probably saved an engine with one. Trans T is another one to watch if Ur hammering on it..
 
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