Autonerdz forums

Alex,

I made this motorcycle board for you and other motorcycle techs.

Not often is looking at a single input very useful.  I suggest you choose several inputs and outputs based on your knowledge of how that system works.

Also avoid using AC coupling unless you have a really good reason to filter out the DC components of the signal.

I am aware that a single signal is not useful but, I am learning how to hook up the different cable, I am is still in that stage where you have to look back and forth for casble codes and ways to adapt the car picture versus the a monocylinder engine Today I hook up the scope once again IN DC mode to the pulse generator, nothing abnormal  about the signal, is just a magneto passing thru the pulse generator all I hope is to get this signal right before procceding any further, since all the future channels signals will most probable by reference to this signal.

As for the problem is question is as follows;
We have KTM 690 which comes equip with two ECU´s, one for EFI and a second that takes care of the FLY By Wire stepper motor.

The engine act normal until it reaches the operating temperature, from there on if you has to stop in a traffic light or slow down or try to cruise at part throttle the ignition advance get stuck in 57-60 degrees BTDC, resulting in a very high operating temp, engine refuses to accelerate, if you manage to gain speed in this  advance mode and let go off the throttle it will lock the rear wheel for sure, imaging the 66HP mono cylinder acting like a 50cc four stroke scooter.

I have learned to get the engine out this situation by letting the engine reach redline(8000) in this full advance mode, let go of the throtlle, go down one gear if necessary and letting the revs settle down some and slam the throttle wide open.

Sorry, no dirty TB,
step motor TPS of  by the book (Fly by wire)
Ignition TPS by the book
valve train lash by the book at 0.07 mm and 0.12mm
$2300 AKRAPOVIK exhaust,
compression OK
Injector OK
Thermostat OK
Need to test the coil with the scope, as soon as I learn how.

I suspect the problem resides in the FLY BY WIRE TPS or its step motor.

Like I said above I am brand new with this instrument , I feel the need to go one signal at a time, to make sure I am getting coherent signals for each sensor.

Ground no ground Tom, the pulse generator has two(2) wires, I use the TA000 test lead and pierce both cables  using the The TA007 Insulation Piercing Test Clips, no ground used whatsoever ,  If I am not mistaken my file let see I see nine (9) crank revolutions, don´t forget that this is a single cylinder engine ( stator-rotor), with an idle speed of 1600 RPM`s.

Since the ultimate fault is a hyper advance spark my next attempt is to add the spark event, question is should a measure primary or secondary event?


i had learned That I should not forget to use the 20:1 attenuation for either case,  and for the secondary I should be grounded to the vehicle battery,  that makes the  Secondary Ignition Pickup (PP178) the only choice for the secondary that much I know, but which cable for primary????

tom  thanks for your time, I am struggling to find extra time  to learn, and the same time fix the rest of my clients needs.

AlexE wrote on Oct 2^nd, 2012 at 8:27pm:


sounds like an issue with the program in the ecu  .  i mean, if the throttle cables are free to move, you've just about covered your bases. 

does this thing have a tps for the throttle body and a position sensor for the throttle cable?  for example, modern 'fly by wire' cars use an accelerator pedel position sensor and a throttle position sensor.  is that the case with this motorcycle?

i suppose scoping the tps sensor(s), as well as the lambda/oxygen sensor might provide some clues. 

Alex,

AlexE wrote on Oct 4^th, 2012 at 6:54pm:


The standard test leads are the colored ones you attach directly to a signal wire.

AlexE wrote on Oct 4^th, 2012 at 6:54pm:


Not sure what you need to know.  Any direct scope connection to secondary coil voltage will immediately destroy the scope and possibly the PC as well.

The PP178 secondary pickups do not attach to the circuit directly but are designed to pick up the signal capacitively through the insulation.  The result is approx 100mv per 1000 volts or 10,000:1.

Tom, I better be  safe than sorry.

AlexE wrote on Oct 4^th, 2012 at 8:21pm:



Right.  You place it on the spark plug wire as you show in your picture.

Just probe one of the wires on the sensor.  Otherwise you ground out the sensor to the other channel ground (ground loop).  Channel grounds go to bat neg.

If you can backprobe the connector this is preferred to piercing the wire (less potential for damage).