Picking up injection pulse on #1 injector line for timing
Picking up injection pulse on #1 injector line for timing
(OP)
Hello:
I have seen a tool at Snap-on (p/n MT257A) that wraps around the #1 high pressure injection line. This sensor will pick-up the timing of the firing of injector #1 so that the user may time the vehicle.
Does anyone know how this device works? I would like to build one instead of paying $500 for a tool that I will use once or twice in my life.
I have seen a tool at Snap-on (p/n MT257A) that wraps around the #1 high pressure injection line. This sensor will pick-up the timing of the firing of injector #1 so that the user may time the vehicle.
Does anyone know how this device works? I would like to build one instead of paying $500 for a tool that I will use once or twice in my life.





RE: Picking up injection pulse on #1 injector line for timing
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Picking up injection pulse on #1 injector line for timing
I am unsure of the type of sensor used but once this is figured out the downstream electronics will be quite easy to make.
Chances are it will be a simple voltage follower with some gain and perhaps a schmitt trigger to square off the wave depending on what the timing light requires.
RE: Picking up injection pulse on #1 injector line for timing
RE: Picking up injection pulse on #1 injector line for timing
In any case it would be simpler to get a set of connectors to pick off the signal.
If it is a mechanical system you might look at a piezo pickup (perhaps a crystal microphone) and listen for the injection pulse. Then you have to determine at what level signal the injector is considered open.
RE: Picking up injection pulse on #1 injector line for timing
Yes I am trying to find injector timing off of a mechanical system. The crystal microphone sounds like an interesting way of picking up that signal.
I will scope one out. I am guessing that that signal will contain quite a bit of ambient noise as well, hopefully the injector pulse will be obvious.
I would also guess that the waveform would indicate the when the injector opens. Perhaps I will be doing some DSP work as well.