Llamai

I hooked up my laptop to my 95 LT1 and noticed that the TPS voltage reading while at idle keeps bouncing up and down by about .2 (.30 - .50 or so). The % also keeps going up and down between 0% and 4%. It won't stay at an exact number. Could that be a problem causing my IAC valve not to operate properly? Because the car idles very high usually.

shbox

The TPS reading should not move if the throttle is not being moved. It could affect idle on its own.

Llamai

I just replaced the TPS sensor, but it still fluctuates between 0,1,2, and 3% at idle, without touching the throttle. Even with the car off the voltage fluctuates within a .10 range. What could be causing this?

shbox

Check your wiring/connections. I've never seen that on a scanner.

96TransAmboosted

iTrader: (8)

Is everything else good? Battery charging correctly, good battery? I have only seen this one time on a turbo pt cruiser with a bad cell in the battery. But Chrysler are very finiky about voltage.

Llamai

The battery only starts charging once I flip the headlights on, which I find strange. And then the voltage stays around 12. Is that too low?

shbox

If the alternator is charging the system, it is going to be 13+ volts. If it is not, the alt is not working. Use a meter to check-don't depend on the gauge.

Llamai

I was going by what the scanning tool says. The gauge says about 11.. If it isn't 13+, my alt may be bad?

shbox

There can be some voltage loss through the circuitry getting to the PCM. It's a common thing. Check it with a meter at the battery. Either way, sounds like the alt is not working. Have it tested.

Llamai

I've been driving it like this for over a year, so it is definitely keeping the battery charged. Perhaps not enough... I will check out the voltage.

96TransAmboosted

iTrader: (8)

Issues with the ternator can cause funny things to happen if the battery starts to run low,

Llamai

The voltage at the battery when the car is running is right at 14v. So the alternator is working...