Automotive Oscilloscope

[Imp558]

Anybody ever use one of these scopes?

I would like to know if it's total garbage before I buy one:

http://m.tomtop.com/hantek-1008a-usb-8ch-oscilloscope-programmable-generator-vehicle-testing-24msas-e0608.html?aid=gpla&gclid=Cj0KEQjwqZKxBRDBkNmLt9DejNgBEiQAq8XWPjJuDafYNBO5_Gj9Qq1A9XAM-n87t90jAYQLaLTz4zQaAoFl8P8HAQ

[55trucker]

I've used the *ancient* old style CRT screen Snap-on analysis units, but those pre date computerized electronic systems. 

 

 

 

the one you've found looks as tho it is incomplete, it seems to be missing the ignition capacitive probe attachment which is necessary.

 

Good item to have in your *toolbox*, being able to *see* what each cylinder is doing when it's firing is very useful for diagnostics.

 

as long as you've a laptop ......for $120 to diagnose your engine ...money well spent.

 

not familiar with Hantek

 

 

http://www.ebay.com/itm/8-Channel-PC-USB-Digital-Storage-Automotive-Diagnostic-Oscilloscope-Hantek-1008C-/141440288760

[Imp558]

Yeah, I saw them on Ebay, for the savings I figured on making my own probes like this guy did:http://www.ford-trucks.com/forums/1159255-poor-mans-cop-scope-probe.html

 

It would be cool to scope all the cylinders at once. I think I'm going to buy it and order some parts from Mouser to make variants of his probe.

Mine will clip onto the wires rather than just be held in place.

[Schurkey]

1.  I'm mystified as to how you'd get the primary ignition pattern.  Looks to me like this is "secondary" only.  Then I wonder if you get raster and parade, or only parade.  Can you select one "channel" (cylinder) to view independently?  Can you superimpose two or more channels?

 

2.  I think this could be useful for fuel injector waveforms, HVAC motor or electric fuel pump (any electric motor) waveforms, and perhaps other uses on the vehicle--but--are you able to find vacuum probes, amperage probes, etc.?

 

3.  NO MISTAKE, a 'scope is teriffic for looking at all sorts of electrical issues on a vehicle, beyond the secondary ignition pattern.

 

 

 

 

 

 

I just LOVE using an automotive oscilloscope--I have an ancient Snap-On Counselor II with a nearly-full compliment of accessories.  The Snappy does not do raster, which I kind-of miss.  I've learned to deal with that minor shortcoming.

 

Keep in mind that this Snappy also does cylinder-balance testing, has on-board KV comparisons, cylinder-to-cylinder timing variations, and "talks" to the equally-ancient "Red Brick" scan tool.

[Imp558]

I haven't used one in 20 years but I've always wanted one of my own. Today I ordered all the stuff to make 8 inductive pickups based on the diagram in the link above. I'll be ordering the actual unit in a few days.

[Imp558]

On it's way! From China, lol, so it'll be a while.

[Imp558]

I played with this thing yesterday, it wouldn't give me a good trace with the inductive probe that came with it or either of the prototypes I made. As of now I'm attributing my really nice plug wires.

Any way, the scope works, it's just a matter of figuring out how to use the probes

[Schurkey]

So...ummm...what "really nice" plug wires do you have?

 

My Snappy has no problem picking up a signal from any plug wires I've tried it with--solid core, carbon core, or helical-wound.

[Imp558]

Taylor Spiro Pro, and it's not a nice pickup, it's a cheap Chinese one. There's still a chance the probes are junk.

[Imp558]

Just an update, ran some more experiments today. I hooked the Hantek up to a function generator today and it looks really nice. It's a bit glitchy in WXP-SP3 and I have to give the Windoze salute from time to time (CTRL ALT DEL). I enlisted a friend of mine who is an engineer and he agrees the Hantek inductive probe plain doesn't work, and feels the inductor in that the diagram I followed (1mh) was way too small so we're re-designing the pickup with a larger inductor and I'd like to get some rectification in there too. All in all the clamps work out really good as bodies and had plenty of room inside them for electronics. Here's a couple pics of my probes that didn't work, they are the same with 2 different styles of inductor.

 

[Imp558]

This turned out to be a really cool little project. I have less than $200 into this and I put a little bit more time in today and got a good working prototype. All the circuit I pulled off the other forum needed was a little rectification to get the signal strong enough removing a resistor that was dropping it and I had to put a ground up at the engine to get rid of the noise. So now I'll be able to scope up to 8 cylinders simultaneously.

[rich_e777]

I had an old bench top scope but it was super ancient and finally gave up before I learned how to read one, now I forgot. I wish I would have kept it to see if some could/would fix it, it had a plethora of settings to it.

[Imp558]

It's been a long time since I did this in school. Does anybody know of a quick reference poster for automotive oscopes I can get to hang up at work?

[Schurkey]

It's been a long time since I did this in school. Does anybody know of a quick reference poster for automotive oscopes I can get to hang up at work?

Going to make a big difference as to what sort of waveform you're viewing.

 

Aside from ignition secondary, (single-cylinder, raster, and parade) there's ignition primary, (single, raster, parade) alternator and starter.  Then there's the smaller electric motors--electric fuel pump, HVAC blower motor, etc.

 

Then there's 'scope viewing of vacuum/pressure probes, and current (amperage) probes.

 

I had a years-old magazine article on 'scope patterns for ignition systems; I've been looking for that article on-and-off for over a year.  I suppose it got thrown out during "housecleaning".  It was printed in an auto-service "trade magazine".

[RobertISaar]

some of the ford service manuals I have access to give reference scope patterns for a few items.... not very comprehensive though.

[Imp558]

Going to make a big difference as to what sort of waveform you're viewing.

 

Aside from ignition secondary, (single-cylinder, raster, and parade) there's ignition primary, (single, raster, parade) alternator and starter.  Then there's the smaller electric motors--electric fuel pump, HVAC blower motor, etc.

 

Then there's 'scope viewing of vacuum/pressure probes, and current (amperage) probes.

 

 

Exactly, a poster with a bunch of waveforms showing different tests and conditions would be awesome to have, It doesn't appear to exist though. I talked to a kid at the local UPS store here, if I take images from the internet and compile it on my own they can print large items.

 

I got all of the circuit boards assembled today, modified all the clamps, cut and prepped all the wires including grounds and assembled 3 probes less ground clamps. The prototype really just needs a better ground wire and then it's ready too so essentially I have 4 done-ish and 4 ready for final assembly. I've decided not to epoxy pot the boards until they are all tested for obvious reasons.

[Imp558]

Found a good reference site for secondary ignition patterns:

http://www.searchautoparts.com/motorage/training/scoping-secondary-ignition-systems

 

Click the author's name to get 3 more articles and visual references.

[Schurkey]

I had a years-old magazine article on 'scope patterns for ignition systems; I've been looking for that article on-and-off for over a year.  I suppose it got thrown out during "housecleaning".  It was printed in an auto-service "trade magazine".

 

 

Found a good reference site for secondary ignition patterns:

http://www.searchautoparts.com/motorage/training/scoping-secondary-ignition-systems

 

Click the author's name to get 3 more articles and visual references.

That MIGHT be the article I've been looking for!

[Imp558]

That MIGHT be the article I've been looking for!

Try clicking on the guy's name, he has more articles. That guy's a badass.

 

I had an interesting experience today. Scoped two of the cylinders on the regal and the patterns were absolutely crazy. Then I started looking at them later on in a picture I had taken And realized they almost look upside down so I inverted them in a photo editor (Gimp) And they looked pretty close to normal. I think what I was seeing is two of the cylinders that are firing opposite polarity, lol. I thought maybe there was something wrong with the probes and I made but I actually got the one that came with the scope working today. It seems to work halfway decent if I tweak the horizontal and the multiplier a little bit But it shows virtually the same trace is mine. I have a little more testing to do but I think I'm going to call this experiment a success

[Schurkey]

Waste-spark ignition uses a single ignition coil to fire two cylinders.  One cylinder of the pair fires normally, one cylinder of the pair fires in "reverse polarity".

 

Normal spark is described as the ignition pulse firing from center electrode to side electrode, then grounding through the plug shell, cylinder head, and onward.  Reverse polarity is described as firing from side electrode to center electrode.  Firing in "reverse polarity" requires higher voltage because the geometry of the spark plug is less efficient when fired "backwards".

 

When you look at the firing path for a waste-spark ignition system, there are two high-voltage towers on the coil, two spark plug wires, two spark plugs, and one or two cylinder heads with attached block and intake manifold, etc between them.  The spark pulse travels from one high-voltage tower, down the plug wire, to the plug where it fires in normal polarity--from center to side electrode.  The spark pulse then travels through the cylinder head and engine to the shell of the companion spark plug, from side electrode to center electrode, up the plug wire where it returns to the coil via the other high-voltage terminal.  ONE spark jumps two spark plug gaps in this circuit.

 

If you had your 'scope connected to the reverse-polarity plug on that ignition coil, you bet the waveform is upside-down.  Dedicated automotive 'scopes have circuitry that flips the 'scope pattern "right side up" so it looks normal.

[Imp558]

I never posted an update to this, it ended pretty awesome with 8 home-made pickups and a few other useful probes in a nice case from HFT.

 

I'm calling this a success, 3800 coils are a bit funny to view because of the reverse polarity on 1/2 the secondary but I can use it accurately.

Worth the $200 investment for me.

 

 

[Padgett]

Neat to have something portable. Personally love test equipment and tube testers & have way to much. Have a couple of Tek scopes, a DSO Nano, SainSmart DDS120, Heath ignition analyzer, and one of these: