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poloracer877

Active Member

• Mar 27, 2013

• #1

Hi can anyone help me please, looking at the injector wiring on race the eight fuel injectors get 12v feed from fuse 1, under bonnet fuse box and the earths are pulsed by the engine ecu, can anyone tell me if you put a multimeter across the two injector wires whilst ticking over, what voltage should pulse,

 

Mr Noisy

Coming in your ears.

• Mar 27, 2013

• #2

I would have thought most multimeters won't react fast enough to properly read it, I was under the impression it was 12v!

 

listerdiesel

Well-Known Member

Events Planner

• Mar 27, 2013

• #3

It's going to be almost a square wave if you look at it on a 'scope, it's on for injection and off the rest of the time, so you should get a decent trace.

If you use a meter on DC, it probably wouldn't be fast enough for the rise and fall of the signal as Mr Noisy has said above, and if you use a meter on AC, you'll get an average value unless the meter is a True RMS type.

Peter

 

Mr Noisy

Coming in your ears.

• Mar 27, 2013

• #4

Nice info

 

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Disgoo

Active Member

• Mar 28, 2013

• #5

Unless you DVM can do a peak hold reading??
Cos you are looking for pulses in the range of milliseconds.........

 

listerdiesel

Well-Known Member

Events Planner

• Mar 28, 2013

• #6

Disgoo said:

Unless you DVM can do a peak hold reading??
Cos you are looking for pulses in the range of milliseconds.........

Click to expand...

I don't think that would be a lot of good in the OP's case.

Our Flukes have hold function, but it's a moment in time, not continuous reading.

Peter

 

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eightinavee

Well-Known Member

• Mar 28, 2013

• #7

Yer need a Picoscope !!
Pico Automotive Diagnostics Kit - the ideal automotive diagnostic tool for your workshop
Fantastic tool,still finding functions it has.I've used it on engines made from 1912 up to date,the answers it gives are honest snapshots of what is ACTUALLY going on,often there is no other way to view these things.Takes over where a scanner ends.