guages gone wild
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Junior Member
Joined: Aug 2010
Posts: 11
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From: Roselle, IL
Car: '88 Z Clone
Engine: 305 TBI V8
Transmission: 700R4
Axle/Gears: 2.73 Limited Slip
guages gone wild
Please help!
I just purchased a 91 rs camaro with the tbi 5.0 the car runs great but the gauges are screwy.
the speedo bounces in first gear then spins to the end after abt 10mph. (i checked the speed on my gps)
the tach always shows im doing either 3000 or just drops.
the gas guage and volt guage always show full and 18.
the temp. gauge appears to be working fine but am not sure if its a hoax.
has this happened to anyone before and if so, how do i take care of this issue?
I just purchased a 91 rs camaro with the tbi 5.0 the car runs great but the gauges are screwy.
the speedo bounces in first gear then spins to the end after abt 10mph. (i checked the speed on my gps)
the tach always shows im doing either 3000 or just drops.
the gas guage and volt guage always show full and 18.
the temp. gauge appears to be working fine but am not sure if its a hoax.
has this happened to anyone before and if so, how do i take care of this issue?
Supreme Member
Joined: Jan 2006
Posts: 3,341
Likes: 10
From: Mooresville NC
Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
Gages Gone Wild
First make sure all the powers and grounds going to the dash are good.
If they are do some testing.
Here’s how to test the fuel gage.
Remove the sender wire going to the gage.
Tape the bare end of the sender wire so and put it aside.
Use a potentiometer with a value of 90Ω or the closest you can find.
Connect one end the potentiometer to the gage from the location you removed the sender.
Connect the wiper of the potentiometer to ground.
Turn the key to RUN.
Slowly adjust the potentiometer from 0Ω to 90Ω.
If the gage is bad it will exhibit the problem you have.
If the gage is good it will display a smooth transition from one end of it’s range to the other.
Therefore the problem is with the sender or wiring going to it.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Voltmeter: First verify the alternator is not putting out 18 volts with a test instrument quality meter.
Then replace the voltmeter.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Speedometer:
It might be a bad VSS.
You can monitor the output of the VSS with an audio amplifier to make sure it’s putting out a steady signal.
Connect the amp’s input to the output of the VSS as you would a CD player.
Ground to ground, the signal wire to the inner wire of the audio amplifier wire.
When driving, or simulating VIA having the car on a dyno, you will hear a hum which increases in pitch when the wheels ate turning faster, if the VSS is good.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Tachometer: There is circuitry in the dash near the tach.
It’s contained on a small plug-in PCB or integrated in the main board.
On the PCB you’ll see a resistor chip.
Desolder pins 4 & 10.
Use a 500K potentiometer.
Solder it across traces 4 & 10.
Move the potentiometer to half way.
Start the engine and compare the tach reading with a test equipment quality tach.
Dial it in, unsolder the potentiometer, measure it and install a matching resistor.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
He Must Have Been Be Cheating - Because I Was And He Almost Beat Me.
.
If they are do some testing.
Here’s how to test the fuel gage.
Remove the sender wire going to the gage.
Tape the bare end of the sender wire so and put it aside.
Use a potentiometer with a value of 90Ω or the closest you can find.
Connect one end the potentiometer to the gage from the location you removed the sender.
Connect the wiper of the potentiometer to ground.
Turn the key to RUN.
Slowly adjust the potentiometer from 0Ω to 90Ω.
If the gage is bad it will exhibit the problem you have.
If the gage is good it will display a smooth transition from one end of it’s range to the other.
Therefore the problem is with the sender or wiring going to it.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Voltmeter: First verify the alternator is not putting out 18 volts with a test instrument quality meter.
Then replace the voltmeter.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Speedometer:
It might be a bad VSS.
You can monitor the output of the VSS with an audio amplifier to make sure it’s putting out a steady signal.
Connect the amp’s input to the output of the VSS as you would a CD player.
Ground to ground, the signal wire to the inner wire of the audio amplifier wire.
When driving, or simulating VIA having the car on a dyno, you will hear a hum which increases in pitch when the wheels ate turning faster, if the VSS is good.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Tachometer: There is circuitry in the dash near the tach.
It’s contained on a small plug-in PCB or integrated in the main board.
On the PCB you’ll see a resistor chip.
Desolder pins 4 & 10.
Use a 500K potentiometer.
Solder it across traces 4 & 10.
Move the potentiometer to half way.
Start the engine and compare the tach reading with a test equipment quality tach.
Dial it in, unsolder the potentiometer, measure it and install a matching resistor.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
He Must Have Been Be Cheating - Because I Was And He Almost Beat Me.
.
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