Motor Age How2 #14 - Exploring The Injector Circuit, Pt 1

[@motorcyclesandridingfree2899]

I will be at AutoMekanika again this year. The first one was great

[@billyr9840]

Nice ! Pete, that is a pretty nifty idea grabbing the ground side of the injectors when the power side at the fuse has other components on it too ! I've seen on other channels where they said you can't look at it because other components were also powered up by the same fuse and gave up on that approach ! Another approach would be to squeeze all of the injector power feeds at the computer into your amp clamp !

[@MotorAgeMagazine]

There is the one power feed, though, Billy, and to access the splice to separate them would require digging into the harness - too much work! :-)

[@JahanZeb1976]

Great information provided. Thanks for sharing.

[@IsshmanGarcia]

Thanks for the video. quick and concise.

[@kirkwest6654]

i remeber the coil amp test with the clamp meter the scope was set to 2v i see that now the scope is set to 2A setting whats the difference?

[@eriginez5171]

great vidio...awsom instructor

[@kimokahikolekalihi]

You can do this by backprobing the connector at the injector, too. Right? Don't have an amp clamp yet.

[@MotorAgeMagazine]

You'll get the voltage pattern but not see the opening hump you can see in the current pattern. And be careful to know your scope's limits OR use an attentuator.

[@albertsautodiagnosticsllc2130]

What training do you recommend for European diagnostics

[@MotorAgeMagazine]

Diagnosing an automobile is the same, no matter what brand is on the car. If it runs on gas or diesel, it has to do certain things a certain way at a certain time. Start by making sure your foundational understanding, especially electrical, is solid and build from there.

[@smms1276]

👍 THANK YOU 👍

[@davidpaterson6318]

Did you not mean 200 Volts per channel for the new PicoScope? You said 100 Volts :( There is no need for attenuation with the latest PicoScope when measuring injector voltage!

[@MotorAgeMagazine]

I was referring to the 4000 series. I was not aware they come out what the new model with a higher voltage intake level. Thanks for making me aware of that.

[@davidpaterson6318]

You're welcome: Full specifications here with details of increased sampling rate of 400MS/s, higher memory buffer 250M Samples; Floating grounds; and of course ConnectDetect® ! www.picoauto.com/products/automotive-oscilloscope-kit/picoscope-4000-series-specifications

[@billyr9840]

I was about to correct Pete too until I saw your post but I believe the earlier Pico was 100v and now they are ±250 V (DC + AC peak) on single input. That is why they use to sell a 20:1 attenuator now they only sell a 10:1 attenuator.

[@davidpaterson6318]

The previous scopes did indeed have a maximum input per channel of ±100 V - and before that ±50 V - both of which therefore require(d) some attenuation because of the high induced voltage when the injector is turned off. (Attenuator still required for primary ignition systems!) However, both the 2 and 4 channel 'Rainbow' scopes - out now for a couple of years - have a ±200 V input per channel capacity - NOT ±250 V! (May be you are confusing the overload protection built into PicoScope?) The sure way to identify these newer 'Rainbow' scopes is that they have coloured 'rings' near the BNC connectors: blue and red with the 2 channel scopes; and blue, red, green and yellow in the case of a 4 channel scope. As a point of note, and whilst this might change, at the time of writing and when running the software in demo mode on your PC WITHOUT a scope connected you will still see a max voltage input of only ±100 V. But, plug in a 'Rainbow' scope (I haven't tried an earlier one!) and you will see that the maximum voltage does indeed display ±200 V. (400 V Peak to peak) Once again, here is a link to the specifications of the current scopes: www.picoauto.com/products/automotive-oscilloscope-kit/picoscope-4000-series-specifications Hope this is clearer!

[@billyr9840]

Nice ! It seems your a bit more knowledgeable than me on this subject than I. Thanks for the info and you are right I was confusing it with the overload protections. Do you work for Pico ?