Robertio

Can anyone advise if this scope of the cam and crank sensors on an LS1 is OK?




Voltage may be different to normal as it is powered by a Motec, but as I don't have a known good graph to compare it against I don't know if the wave pattern is correct.

sreve

iTrader: (3)

Here's one

joecar

Here's another one...

joecar

Can you set you oscilloscope to a higher sample rate and capture a new waveform...?

Robertio

Unfortunately not at present - I only have a cheap rubbish USB scope, if I increase the sample rate I lose duration Will try to track down a half decent one.


Thanks for the graphs

joecar

The Picoscope 3424/4423 automotive USB oscilloscopes have high sample rates and deep buffers.

Big Al

iTrader: (1)

Just googled that. Holy Cow Bat Man! You can buy a decent lab scope for less.

Al

Robertio

Unfortunately I had a similar reaction - it's a lot of money for something I'd very rarely use. I'm more inclined to put the money towards a Syvecs ECU instead which has scoping output built in.

joecar

Find someone who has one.

edcmat-l1

iTrader: (10)

That Pico unit is a helluva nice tool for the price. I've got the Vetronix MTS5100, which was almost 3 times the price of the Pico, over 10 years ago.

http://www.boschdiagnostics.com/test...s/MTS5200.aspx

This is the newer version. Vetronix has since been bought by Bosch.

joecar

The MTS is a very capable tool.

I didn't realize Bosch bought out Vetronix... so Bosch is now GM's electronic tool supplier...?

joecar

The cheap scopes are usually 8 bits and don't have deep buffers (let alone 4 channels)...

I can understand why a DIY would not buy an expensive scope... by mentioning the Pico I was hoping you could find someone who did have a like scope.

edcmat-l1

iTrader: (10)

I think Vetronix is still intact, just owned by Bosch.

Vetronix writes the diagnostic software for a lot of OEs. GM is just one.

Big Al

iTrader: (1)

Used scopes are available for under $100 if you look. I paid $60 for a 10MHZ Hitachi and I put it in my roll around cart. Use the hell out of it. Couple weeks ago I was looking at the waveform from a MSD flying magnet crank trigger and found it was wobbling. And it wasn't what I thought, the crank shaft nose was being bent by an out of flat washer between the crank and the balancer. If someone told me that I would think they were nuts. Also found the MSD 7AL had a bad ground.

Cheap tool for what it does....

The only advantage I can think of that a computer based scope would have is the ability to store, share or print out waveforms. And I can't say that's not a worthwhile advantage.

Al

94camaroz28lt1

iTrader: (1)

I'm working on a project that I am emulating a PCM on the bench, I need a 24x crank signal, and maybe the 1x cam signal from a LS1 motor

Would you beable to send me those in a WAV format? So that I can play it back through my PC sound card and into the crank sensor?

joecar

The file format is .psdata (i.e. picoscope data file)... it seems the picoscope software can't save as .wav (that I can see).

94camaroz28lt1

iTrader: (1)

Could you send me the psdata file? I have a trial Pscope program.. not sure how or if it is possible to convert it to sound file and or play it back..

I have the tach moving but it isn't very smooth I suspect because file I am playing back is 24 evenly spaced teethe were is it should be 24 teeth two sets space 15 degrees that are 12-3 degrees apart.

I wish there was a way to convert the JPEG into a wave form, The wave is exactly what I need to create.

joecar

The file is 1.35MB... pm your email address.


You can download the actual picoscope software from their website.

joecar

They are not symmetrical or evenly spaced...

if you look closely at the waveform you will see that:
- in each 360° there are 4 quadrants;
- in each 90° quadrant, there are 6 segments that uniquely encode that quadrant;
- in each 15° segment, there are 2 pulses, 3° and 12°, in either order, with opposite sense to each other.