Testing electrical current to fuel injectors

Gotta love that wiring . . .
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FiatnamedCarmen

Testing electrical current to fuel injectors

Post by FiatnamedCarmen »

Hi everyone,
Well we are getting really close to having a running car (fingers crossed)
After sitting for nearly 10 years! Current issue: number one and two cylinders are not firing. Already changed fuel injectors. How do you confirm current is getting to ejectors? Compression is good. Changed spark plugs, wires and checked all timing. Any other suggestions? Thanks in advance!
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toplessexpat
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Re: Testing electrical current to fuel injectors

Post by toplessexpat »

"Noid" lights....

There's a few different types, make sure you get the Bosch ones, or get a set (when I bought mine it was less than $10 to get a complete set for many different applications (http://www.carid.com/powerbuilt-hand-to ... 95774.html)

Andy
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RRoller123
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Re: Testing electrical current to fuel injectors

Post by RRoller123 »

You can clearly hear the "click" of the injectors with an inexpensive mechanic's stethoscope too.

Pete
'80 FI Spider 2000
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amawds

Re: Testing electrical current to fuel injectors

Post by amawds »

I'm assuming you could also simply pull them, plug them in and physically feel them click while watching the valve open up.
GeorgeT
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Re: Testing electrical current to fuel injectors

Post by GeorgeT »

A simple noid light will show if you are getting current to the injectors: pull the lead off the injector, put one wire from the noid light in the lead and ground the other wire; crank the motor and if the injectors are being energized, the light will flicker (use a tungsten filament bulb). Check each lead.
majicwrench

Re: Testing electrical current to fuel injectors

Post by majicwrench »

You DO NOT ground one of the noid light wires.

A noid lite goes between the two wires at the injector.

You cannot "watch" an injector open.

The connector at the injectors are prone to failure. YOu can buy new connectors from any good parts store. If they cannot find the part number for you, go somewhere competent or I will find part number for you.
wizard124
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Re: Testing electrical current to fuel injectors

Post by wizard124 »

If I remember correctly, I used a multimeter. Use a mV DC scale. As the engine cranks, you will see the reading fluctuate. This indicates the ECU is sending the ground to the injector.
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RRoller123
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Re: Testing electrical current to fuel injectors

Post by RRoller123 »

And the vendors here , AR I know, sell new connectors.
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle
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toplessexpat
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Joined: Fri Aug 31, 2012 2:29 am
Your car is a: 1976 Spider 1800
Location: Houston, TX

Re: Testing electrical current to fuel injectors

Post by toplessexpat »

Be careful if using anything apart from the bosch noid - you don't want to accidentally force in a multimeter probe and open up the socket on the injector so it doesn't fit snugly anymore.

A
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GeorgeT
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Joined: Thu Feb 16, 2012 12:41 pm
Your car is a: 1982 Fiat 124 Spider

Re: Testing electrical current to fuel injectors

Post by GeorgeT »

majicwrench wrote:You DO NOT ground one of the noid light wires.
Correct, my fingers got ahead of my brain!
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