Is this normal (video clip)

[RoCa]

Good evening everyone, I have a 1975 280z which is making this electrical noise and it seems to be coming from the efi. Is this a normal noise since the car is old or is it something that can cause a problem? The car runs and drives fine, the efi are pretty responsive as well. Pls let me know you input.http://youtu.be/kOyzsGtac8o!

Edited August 1, 2013 by RoCa

[Virto]

Hard to make out the source of the high-pitched squeal. Might be easier to pinpoint the area it comes from via ear versus the mic on the camera.

If it's a metal on metal squeal, it could be the water pump or something else that turns with engine rotation.

I *THINK* the early 280Z were equipped with a resistor or relay or something that was designed to keep the electronic noise from being picked up by the radio - I'd have to look into it to be sure.

[RoCa]

Hard to make out the source of the high-pitched squeal. Might be easier to pinpoint the area it comes from via ear versus the mic on the camera.

If it's a metal on metal squeal, it could be the water pump or something else that turns with engine rotation.

I *THINK* the early 280Z were equipped with a resistor or relay or something that was designed to keep the electronic noise from being picked up by the radio - I'd have to look into it to be sure.

Definitely a electronically noise and not a metal on metal noise. It goes on and off at every level rev of the engine as seen on the video. I tried listening to it as close as I can and it's coming from the middle of the engine bay, around the efi rails.

[beermanpete]

I can hear the noise you mention. Just to hazard a guess: Based on your description and the noise in the video it could be a problem in the ECU that is allowing an oscillator or clock signal out to the injectors and the injector coils are ringing in response to the signal. If you have the capability connect an oscilloscope to the injector wiring and look at the waveform. I know this might seem wierd and unlikely but it came to mind. FWIW.