No bench test Tach pickup

[boxertwin]

Another of those I can't get crank tach pickup queries. I have 2 Microsquirts one a very early V2 with 2.880000, and a later V2 with 2.88600 (it has a black/navy blue board with V2 C 2007 and 2009). The early one has been running very successfully on a 2-stroke twin for a number of years now - no problems. The second was bought as a 'spare' and has never previously been used. I recently decided to use it on a 700cc Boxer twin (4 stroke), and am in the process of setting it up. I have it on the bench wired up to a JIMSIM (which was used to set up the first Microsquirt) using tunerstudio 1.006, I can talk to the ECU and change all of the variables (MAP,CT,AT, etc - (O2 no)) - no problems - except it wont register the crank signal (which is supplied from the JIMSTIM with a 12V pull up on the VR input - and there is a thumping nominally 12V 36-1 signal going all the way into the correct pin 32 of the AmpSeal, with ground into pin 33 - into the ECU board. Have checked through almost everything I can think of and it still will not register a signal (i.e. no rpm or injection and no spark output), I have even downloaded the running .MSQ setup for the working ECU on the 2 stroke engine into the second ECU - still no ignition pickup! and that configuration, variables and maps are fully working on the early Mucrosquirt!

Ignition setup: - Predictor settings - Alph% 90, Beta% 80 Gamma% 10
Tau Sigma masking 00ms,, Mask 70%
Next Pulse Tolerance Cranking 50%, After Start 70%, Normal Running 25%
Ignition Capture - Rising
Crank Trigger - calculated
Coil Charge - Standard Coil Charge
Spark output Going High (inverted)
Timing Wheel - 36
Missing Teeth - 1
Skip Teeth - 18
Delay Teeth - 0
Dual Spark - Single Crank Wheel Input
Offset Advance - 0.00
Start IAT Retard - 880
Full IAT Retard - 1500
FET Output Delay - 0
VR input delay - 0


I am scratching my head slightly!

As I understand it I can do a wasted spark on the 4 stroke Boxer twin setup with a single double ended coil driven directly by both of the coil outputs of the V2 with a single crank mounted 36-1 wheel?

Many Thanks,,
J

[Matt Cramer]

What sort of sensor are you using?

[boxertwin]

Matt,

The one I am trying to get to work is on the bench and the input is fed from the JIM STIM into the VR input (core of the VR coaxial cable). The JIMSTIM is set with a 12V pull-up and is producing a 12 P/P signal right into the board. The one on the 2 stroke that works is also using the VR input with a Ford pattern VR sensor on a triggerwheel mounted on the dynastart fan (remember the system on the 2 stroke works perfectly!)

The 4stroke boxer twin is being set up with a very similar setup - 36-1 wheel milled into the flywheel, with a Ford pattern VR sensor. (the reason that I thought to try the 2-strokes MSQ - the sensor configurations are (will be) the same!)

The second Microsquirt which won't register the ignition input, is set up on the JIMSTIM, and will not work with either the starting set-up I was working on for the 4stroke boxer twin, or the MSQ setup actually running in the 2-strokes Microsquirt. Hence the reason I am scratching my head.

John.

[boxertwin]

Matt,

Forgot to say that I have captured the signal from the JIMSTIM on a scope and can confirm that I do have the no 3 slide switch 'on' for a 36 -1 ignition signal, and have counted the 35 pulses with a missing one on the scope!

John.

[Matt Cramer]

What JimStim version do you have? You'll need one that can fake a VR signal for the V2.0 MicroSquirt VR input.

[boxertwin]

MAtt,

I have a JIMSTIM V1.3, set up with switch 3 'ON' to give a 36-1 signal, the Pull-Up jumper is set to 12V on 'P', and there is a jumper on the Primary Tach jumper. I have also checked the 12v P/P signal right through the loom down the white core of the VR coax, and into the correct Pin 32 of the AMPSEAL, and this is actually traced through to provide this signal onto the Microsquirt V2 board at the correct point where Pin 32 solders into the board. The JIMSTIM and hence the Microsquirt are being powered by a 12V 5amp laboratory power supply, and I do have the +5V sensor supply linked back into the JIMSTIM into the appropriate connection.

I have also set the signal up and captured it on a scope and can confirm that I do have 35 pulses with a gap, continuously repeated at 12V P/P/being produced by the JIMSTIM, and the JIMSTIM will change the frequency with it's RPM pots. As said, the signal from the JIMSTIM into the Microsquirt seems to be fine, hence the reason I am scratching my head. My first 'squirt was a very early one that had the VR input connections inverted in the wiring loom - this one seems to be correct and have signals that should make the Microsquirt work.

Also, this particular JIMSTIM did work quite successfully when I set up my first (red board) Microsquirt in 2008! and checking back the VR input circuits they seem to be identical between the print-out I made in 2008 and the current V2 circuits on the web.

Many Thanks,

John.

[Matt Cramer]

The V1.3 doesn't have the fake VR jumpers, you'll need to couple it to the VR input through a capacitor (or the Hall offsetter circuit) to make it trigger the VR input.

[boxertwin]

Matt,

Sorry for the delay in replying, I've been on holiday in the Hebrides for the last two weeks and have just got back. Now have a capacitor in place and it is working fine.

Many Thanks

John.