Diagnosing engine problems with an oscilloscope

[volvoskim]

You need a scope with a bandwidth of 20mhz,which will do the the job just fine.The main thing is getting to grips with the controls,and getting the waveform to appear.
Have a good dig through this site autonerdz which I use a lot

http://www.autonerdz.com/cgi/yabb2/YaBB.pl

Have a look on you tube for videos describing the oscilloscopes functions,some great information.

[volvoskim]

Here is a fine little article on analyzing engine performance using HT voltage or in this case the LT side whuch is a direct reflection of the HT

ht analysis very good.pdf

(345.38 KiB) Downloaded 449 times

Here are the links to 4 videos on you tube looking at operating the scope


Pat 1



part 2



part 3



part 4

[volvoskim]

Most sensors you can test with a standard x10 probe, cam sensors,rpm sensors airflow meters etc,but for testing the secondary ht you this unit.


http://www.picoauto.com/secondary-ignition-pickup.html


To test the injectors and the ignition primary you need an attenuator

http://www.picoauto.com/attenuator.html

The injector as an inductive kick of about 60 volts so it needs this to knock the level down so it will fit on screen.Also the ignition primary produces a 300 volt kick that needs reducing

injextor wabeforms.pdf

(718.78 KiB) Downloaded 401 times

[volvoskim]

for anyone wanting to learn about oscilloscopes here,s a great lecture about them on you tube

[JustAsking]

Does anyone happen to have any pictures of what a good or a bad camshaft position sensor would look like on an oscilloscope? My husband has sent me to fetch some. He is trying to figure out what is wrong with my 2001 V70XC. So far, I'm not having any luck.

[volvoskim]

Injector waveform from my 850.
Takes all the guess work out of deciding on injector problems ,this show there is no coil problems or sticking pintles.

[volvoskim]

Does anyone happen to have any pictures of what a good or a bad camshaft position sensor would look like on an oscilloscope? My husband has sent me to fetch some. He is trying to figure out what is wrong with my 2001 V70XC. So far, I'm not having any luck.

An oscilloscope is the best way to decide