NOID vs Test Light

[Joshua M. Smith]

Hey Guys,

I have a test light that will light at 4.5 volts. I should be able to test injector pulse at 5v with it, correct?

My collection of noid lights, floor jacks, scanner, etc. got stolen in a break-in recently. I have no money to spare for a new noid right now.

Thanks,

Josh <><

[GMMerlin]

Injectors are powered by 12volts.

[Joshua M. Smith]

But they receive a reference pulse at 5v from the computer.

At any rate it's checked, the light worked fine, problem solved.

Thank you,

Josh <><

[Rmbodie]

I think the injectors are varied by the voltage . Thus higher voltage is more fuel . there are onlt 2 wires on mine .

[GMMerlin]

Originally Posted by Joshua M. Smith

But they receive a reference pulse at 5v from the computer.

At any rate it's checked, the light worked fine, problem solved.

Thank you,

Josh <><

Well glad it worked out, but I do have a question.
What year and engine are we talking about here?
Any GM vehicle I have ever worked on ( at least 1 or 2) has injectors powered at 12 volts and for the most part the injectors are triggered by the PCM thru the ground circuit to turn on. The PCM varies the on time (not the voltage) of an injector to make the Air/Fuel mixture richer or leaner depending on engine operating conditions.