[axman88]

The day I should need anything more than a voltmeter and maybe an can interface to read out the stored fault codes I am reverting to point´s ignition.

The singles use K-line, so a CAN interface won't do anything for me, and the singles prior to to 2017 don't talk to any scanners or readers.  A voltmeter or multimeter is fine within its limits, but it won't tell the difference between a injector with a stuck pintle and a working injector, and is worthless for sensors that encode their signals digitally or via PWM, or for looking at ignition pulses.

The old ways of doing things, like parts substitution, still works, but it's expensive and time consuming, especially when every part has to come mail order.  The new tools, and some knowledge, can handle the new technology.  The latest generation of auto electronics has sensors that communicate in digital packets, not via varying voltage.  There's none of that in my UCE, probably little to none in any RE, but it's coming.  I want to be ready.  Points and VOMs will still be available for the old dogs that prefer not to have to learn any new tricks.

I just bought a good old Simpson 260, in fact.  I needed it's 5000VDC range, and I'm shopping for a good old high voltage probe so I can measure up to 40kV.

[zimmemr]

The singles use K-line, so a CAN interface won't do anything for me, and the singles prior to to 2017 don't talk to any scanners or readers.  A voltmeter or multimeter is fine within its limits, but it won't tell the difference between a injector with a stuck pintle and a working injector, and is worthless for sensors that encode their signals digitally or via PWM, or for looking at ignition pulses.

The old ways of doing things, like parts substitution, still works, but it's expensive and time consuming, especially when every part has to come mail order.  The new tools, and some knowledge, can handle the new technology.  The latest generation of auto electronics has sensors that communicate in digital packets, not via varying voltage.  There's none of that in my UCE, probably little to none in any RE, but it's coming.  I want to be ready.  Points and VOMs will still be available for the old dogs that prefer not to have to learn any new tricks.

I just bought a good old Simpson 260, in fact.  I needed it's 5000VDC range, and I'm shopping for a good old high voltage probe so I can measure up to 40kV.

All good points here but the one that hit home for me concerned the injectors. In some cases  even the ECU can't tell there's a problem with them. If the injector fails due to a mechanical issue, bad or stuck pintle, broken O ring, whatever, the ECU won't pick it up. So long as electronics are intact the ECU thinks everything is fine. I had a tough time explaining that to some of my younger mechanics, who sometimes thought that if their was no check engine light or DTC's the thing had to be running right.   Sometimes you just have to pull the damn thing apart and take a look at it. 

[axman88]

All good points here but the one that hit home for me concerned the injectors. In some cases  even the ECU can't tell there's a problem with them. If the injector fails due to a mechanical issue, bad or stuck pintle, broken O ring, whatever, the ECU won't pick it up.   Sometimes you just have to pull the damn thing apart and take a look at it.

Or, you can pull out your $68 automotive Oscope with your cheap and dirty probe set, and look at the injector signals, do the diagnosis, order the part, and have it in your hands BEFORE you pull the damn thing apart, like this young lady is doing in this Utube video.   https://www.youtube.com/watch?v=5nBsGBzud0o   Notice she's back probing, it works!  Sure wouldn't want to invest a whole lot of my own money installing an ECU breakout header into somebody else's '86 chevy S-10, although I'm sure that the owner loves it.

I only get blinky code diagnosis with my '12 RE C5, and although other vehicles I might be fooling with may give more information than that, a code that says "engine misfire" can be a lot of things, and hard to find amongst the multiple cylinders, the multiple systems, and the many many sensors in an average vehicle.

My Hantek is quite a bit nicer than this, but a bottom end Oscope like these little, single board jobs, can be purchased nowadays cheaply enough to make  stocking stuffers:  https://www.ebay.com/itm/2-4-LCD-Display-DSO150-Digital-Oscilloscope-Assembled-With-Case-Test-Clip-US/284132195685   My brother says he's thinking of buying one of these for every one of his son's boy scout troop.  They are even cheaper when you buy it as a kit.  He's the "nerdy" dad, and they have an electronics merit badge.

But I'd want one with two channels, so I could compare two signals, like one of these DSO212s  https://www.ebay.com/itm/US-Seller-Nano-DSO212-Smart-LCD-Digital-Oscilloscope-USB-Interface-1MHz-10MSa-s/173883005017   It fits in a shirt pocket, and can help you be ready to take on the new century.

[zimmemr]

Or, you can pull out your $68 automotive Oscope with your cheap and dirty probe set, and look at the injector signals, do the diagnosis, order the part, and have it in your hands BEFORE you pull the damn thing apart, like this young lady is doing in this Utube video.   https://www.youtube.com/watch?v=5nBsGBzud0o   Notice she's back probing, it works!  Sure wouldn't want to invest a whole lot of my own money installing an ECU breakout header into somebody else's '86 chevy S-10, although I'm sure that the owner loves it.

I only get blinky code diagnosis with my '12 RE C5, and although other vehicles I might be fooling with may give more information than that, a code that says "engine misfire" can be a lot of things, and hard to find amongst the multiple cylinders, the multiple systems, and the many many sensors in an average vehicle.

My Hantek is quite a bit nicer than this, but a bottom end Oscope like these little, single board jobs, can be purchased nowadays cheaply enough to make  stocking stuffers:  https://www.ebay.com/itm/2-4-LCD-Display-DSO150-Digital-Oscilloscope-Assembled-With-Case-Test-Clip-US/284132195685   My brother says he's thinking of buying one of these for every one of his son's boy scout troop.  They are even cheaper when you buy it as a kit.  He's the "nerdy" dad, and they have an electronics merit badge.

But I'd want one with two channels, so I could compare two signals, like one of these DSO212s  https://www.ebay.com/itm/US-Seller-Nano-DSO212-Smart-LCD-Digital-Oscilloscope-USB-Interface-1MHz-10MSa-s/173883005017   It fits in a shirt pocket, and can help you be ready to take on the new century.

My apologies, I should have been clearer, though I didn't state it, I was thinking specifically about a HEUI diesel injector. With those you often have a situation where the electrical portion of the injector works perfectly well and will pass every test, but due to bad injector O ring(s) in either the fuel or oil passage or physical damage to the mechanical portion of the injector you end up with a misfire or dead hole. It speaks poorly of my proof reading skills so again I apologize. 

[Karl Fenn]

Well a pulse meter gives you the advantage on being able to read injectors hall sensors, they read the electrical pulses, when it pulses the light flashers, you only need them on a newer bike older bikes you can just use multi meter, a pulse meter is sometimes referred to as a logic probe, it has three LED red, orange, green, it also has capability to measure live circuit up to 18v DC, you can get them on web, they also measure the pulse on injectors and such like where it would be difficult to use meter. You can buy them on eBay.

[Karl Fenn]

They sill listed on eBay they have gone up a bit since l bought mine which was quite a few years ago, just put in logic probe, they changed the pages now do to covid if you put in pulse meter it just comes up finger testing oxygen meters, put logic probe in bar then search then you will see the various types.

[Karl Fenn]

I have a laser type digital gun thermometer came from china, very good for measuring your engine temp or inside your freezer and accurate, l tested it against another so there is no question as to accuracy, that was cheap as chips, also a probe camera you can see inside heads that type of thing, fork tubes, not the best image in the world but does the job that was cheap as well.

[Karl Fenn]

An electronic pulse meter

[axman88]

Well a pulse meter gives you the advantage on being able to read injectors hall sensors, they read the electrical pulses, when it pulses the light flashers, you only need them on a newer bike older bikes you can just use multi meter, a pulse meter is sometimes referred to as a logic probe, it has three LED red, orange, green, it also has capability to measure live circuit up to 18v DC, you can get them on web, they also measure the pulse on injectors and such like where it would be difficult to use meter. You can buy them on eBay.

Yes, had more luck finding this tool as "logic probe".  I see most offer selectable TTL / CMOS modes, which will change the high/low voltage thresholds.  I saw at least one unit that specifically allowed 12V automotive voltage levels, where others aren't specific.

Here's a spec. sheet from what I'd consider a good quality tester from B&K:  https://www.alliedelec.com/m/d/7d0f656b5e7e7cbfde9ce4a2e0d826c1.pdf

I believe that my RE's Keihin ECU operates certain sensor circuits at 5V (TTL?) level, while other circuits, like the fuel injector is operated at 12V.

Seems like, if I was using the B&K DP-21 on the spec sheet, the voltage thresholds would be
              TTL            CMOS (referenced to B+ at 12V)
High      2.30V          8.40V
Low       0.80V          3.60V

Anything in between these values is indeterminate.

Which setting would I want to use, if I wasn't sure what voltage a given circuit I was probing was supposed to be operating at, or does it matter?

[viczena]

I still dont know what a logic probe would tell you on a bike that a simple voltmeter would not do. And you have to attach it to the right voltage source.

[muezler]

I still dont know what a logic probe would tell you on a bike that a simple voltmeter would not do. And you have to attach it to the right voltage source.

+1.....I usually use a logic probe when "repairing" arcade boards and old video consoles...they are good for looking if chips are broken

[axman88]

A voltmeter isn't fast enough to register pulses.  For example injector pulse less than 10 milliseconds will be entirely missed by an analog or digital voltmeter.

However, for that application, and most others, the O-scope will be far superior to the logic probe, giving ability to visualize and analyze the inductive pulse of the injector.

The logic probe is inexpensive and small, and faster than a simple test light,  but not that much cheaper than the latest generation of basic O-scopes like this one:
https://www.amazon.com/DSO-Shell-Oscilloscope-DSO150-15001K/dp/B076HD5862

If I had only one tool, it would be the analog multimeter, which I find superior to the DMM, but it is fragile and not suitable for transporting on the bike.  The only test equipment that I carry with me, as part of the bike's kit is a 99 cent, digital volt meter with a couple of alligator clips leads soldered on.  https://www.ebay.com/itm/174517694133 

[Karl Fenn]

Well for a start a volt meter would not read a pulse of hall sensor, they have a specific function, bikes do not read in volts anymore so it would be impossible to test, l suppose in that situation you would flick the tumblers and see if it reads, l know it does injectors and pulses, but the instructions were not the best in some cases you were flying blind, l will have to do some more study on the full range of usage.

[viczena]

The CPS is a magnetic sensor, not a Hall Effect. It has just 2 wires. It produces a AC sinus waveform of 3-5Volts.

[Karl Fenn]

Well therefore if it gives off a reading of 3.5 AC it would follow it should be rested bmw use an LED on there Hall effect sensors to set timing so that clearly concludes they are testable.