I want to analyze some signals from a certain motor cam signals preferably anyone have any experience? What should I use.

 

I have, what are you testing ?

 

I need to record the signals from my Nissan V8 cam position sensor and crank sensors to give a clear indication of how the engine will trigger the ECU. For use of the active cam control feature on Haltech as the signal is unknown at this time.

What do you use? I need to record these signals and monitor them.

 

I have the Techtronix TDS2024B



It does everything that I need and more, plus it records traces so you can look back and see what's going on. A great trouble shooting tool.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">I have the Techtronix TDS2024B



It does everything that I need and more, plus it records traces so you can look back and see what's going on. A great trouble shooting tool.</TD></TR></TABLE>

Intresting 2 thousand dollar equipment you have there, but if I just want to see a signal from an optical sensor or other few sensors cants I use something cheaper and pc based .

 

Are they mag sensors? Can you see the trigger teeth? What exactly do you need to know about the signal?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Are they mag sensors? Can you see the trigger teeth? What exactly do you need to know about the signal?</TD></TR></TABLE>

I need Haltech to support the VTC active camgears on my Nissan V8.

To do that I need clear indiction of how the engine will trigger the ECU, the optical cam position sensor controls the igntion and the injectrion on this motor, its an optical sensor with a disc that has 360 slits for 1 degree and 8 slits for a 90 degree signal.


The the signals are unknowns as fars as that goes so I wouldnt be able to support it with a Haltech e11v2 ecu.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">
Intresting 2 thousand dollar equipment you have there, but if I just want to see a signal from an optical sensor or other few sensors cants I use something cheaper and pc based .</TD></TR></TABLE>

There are PC based o-scopes. We use them here at work. They are less than half the price of the one I posted.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">

There are PC based o-scopes. We use them here at work. They are less than half the price of the one I posted.</TD></TR></TABLE>

Can you link me please .

 

I guess i'm not sure what you're looking for. If you know how many openings there are in an optical sensor, then you know how many triggers there are. 95% of the time optical sensors are a square wave output, so it shouldn't be hard to figure out what the trigger pattern will look like.

Most of the time the ecu wants to know how many triggers per revolution on the crank. If that's the case, and yours is on the cam with 360 slots, then you would have 180 pulses per crank revolution, right?

When you say 8 slits for a 90 degree signal, is this referring to the "cam" position sensor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">I guess i'm not sure what you're looking for. If you know how many openings there are in an optical sensor, then you know how many triggers there are. 95% of the time optical sensors are a square wave output, so it shouldn't be hard to figure out what the trigger pattern will look like.

Most of the time the ecu wants to know how many triggers per revolution on the crank. If that's the case, and yours is on the cam with 360 slots, then you would have 180 pulses per crank revolution, right? </TD></TR></TABLE>


Yes because of it running half the speed of the crank.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
When you say 8 slits for a 90 degree signal, is this referring to the "cam" position sensor?</TD></TR></TABLE>

Yeah.


To operate the VCT properly I must know:

Edge rising or falling edge signal trigger, Trigger angle and the freqency the solenoid runs at.

These are all depending on what engine of course.

 

Frequency of what solenoid? The variable cam solenoid? The OEM manual MIGHT have that info, but doubtful.

On the edge, generally on a square wave signal you can look at either edge, rising or falling.

I'm not sure what you mean by trigger angle, is that where the cam signal comes after TDC #1?

Most computers want to see a single pulse per cycle for the cam sensor, is that what the haltech is looking for?

The way the engine is setup, when the cam timing moves, does it also move the trigger wheel for the pickup, or is the trigger in a constant spot regardless of cam position?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Frequency of what solenoid? The variable cam solenoid? The OEM manual MIGHT have that info, but doubtful.</TD></TR></TABLE>

Yeah the solenoid for it I'd have to go about finding that out.
I have the manual for it doesnt say.




<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
On the edge, generally on a square wave signal you can look at either edge, rising or falling.</TD></TR></TABLE>

So it doesnt matter what I pick?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
I'm not sure what you mean by trigger angle, is that where the cam signal comes after TDC #1? </TD></TR></TABLE>

As haltech states its the angle between tdc and when the intake cam is at its most retarded position.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
Most computers want to see a single pulse per cycle for the cam sensor, is that what the haltech is looking for?</TD></TR></TABLE>

Roughly + the operational abilites of the vtc assembly.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">The way the engine is setup, when the cam timing moves, does it also move the trigger wheel for the pickup, or is the trigger in a constant spot regardless of cam position?</TD></TR></TABLE>

The active timing are on intake camshafts only. The cam position sensor is on the exhaust camshaft.

 

We use this - http://www.obd2.com/scope/scope.htm



It's a relabeled 2 Channel Pico Scope that can be upgraded to 4 Channel if need be. It's laptop based and has worked great since we bought it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by david@didrace.com &raquo;</TD></TR><TR><TD CLASS="quote">We use this -

It's a relabeled 2 Channel Pico Scope that can be upgraded to 4 Channel if need be. It's laptop based and has worked great since we bought it.</TD></TR></TABLE>

How much did that cost you?

 

The one that Dave has is just under $800.

Pico Technologies has some real nice stuff. If I didn't get a good deal on my Techtronix then this was my next choice.

 

I have seen PC based Oscopes cost between $500-$1k. I'm pretty sure your not going to find an Oscope for less then $500 unless you find a real old used one.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">
On the edge, generally on a square wave signal you can look at either edge, rising or falling.
</TD></TR></TABLE>

It sounds like the signal could be referenced to TDC or something, in which case will make a difference on what edge you use. If you only care about absolute signal then shouldn't matter.

For the solinoid frequency it sounds like they are looking for max switching speed for some kind of limit parameter.

 

TDC is determined by the relationship between the "cam" and "crank" signals, which is adjustable in the software.

The solenoid frequency is the frequency the cam control solenoid operates at.

Have you tried haltech? Sometimes they already have all this information.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">TDC is determined by the relationship between the "cam" and "crank" signals, which is adjustable in the software. </TD></TR></TABLE>

This is in reference to me?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
The solenoid frequency is the frequency the cam control solenoid operates at.

Have you tried haltech? Sometimes they already have all this information.</TD></TR></TABLE>

This is in the haltech manual in VTC parameters.

Haltech has no info on this motor straight from the horses mouth.

 

no, that was to turbosi

 

Sorry to but in adding confusion, I think Tony1's over all point is that you should be able to figure out what the signals are based on mechanical properties rather then buying an expensive tool to measure these sensor signals.

My question was regarding the phase difference between rising and falling edge of the signal representing cam posistion. Since it's pointed out that signal data can be adjusted in software it makes sense.

Gotta find that solinoid frequency though, otherwise you can measure it with an Oscope

 

best thread on HT

 

wow, now i see how old the machine we use at our school really is. it stands about 6 feet tall, 6 feet wide, and 2 feet deep

 

I was actually talking to a friend a while back about something along the same lines... he found a nice cheap scope... it's pretty much all software based. Works well he has been using his for a while... I'll try to dig up the address...

 

Any DSO or graphing voltmeter will do you quite well for a lot of the actual vehicle. The only thing NOT to buy is a DSO that has no record feature, since you would then have to be watching the screen ALL the time in order to see any glitches or dumps. Happy motoring!

Rich