Hi guys

Was trying to remove noise from the 2nd trigger unmodded cas and got a bit carried away with the tolerance between tooth and pickup. Anyway one tooth must have been longer than the others and it broke the tip off.

So to cut a long story short I have modded the cas by cutting two opposing teeth. I've stabbed the cas with 3 teeth after the NE pickup and spent a bit of time trying to get it started. I get rpms and the occasional backfire but wont start. Can someone have a look at my msq to see if my settings for missing teeth are correct?
Thanks

Jono

 

I'm running modded CAS and have just recently upgraded to MS2. Two things that stand out to me are in your "Trigger Wheel Settings". For "Tooth #1 Angle" I'm running 5.0 (though I forget how I stabbed my CAS) and "Wheel Speed" should be Crank Wheel.
When I first upgraded, I had Cam Wheel selected for Wheel Speed and I was barely able to get the car to run. I noticed that my dashboard tach was reading ~1100 RPM and the Tuner Studio was showing ~2200 RPM. Heh, lesson learned.
-John

 

My rpms are reading as expected at around 200 rpm for starting. Twisted rotor are you seeing double rpm all the time???

The settings I have are:

Single toothed wheel,
missing tooth setup,
24 teeth,
2 missing,
rising edge,
trigger angle 0,
tooth 1 angle 60

Cas is stabbed 3 teeth after missing tooth.

Any ideas?

 

Try 12-1 - the CAS wheel runs at 1/2 crank speed and is effectively 12-1 with 2 teeth cut off the 24 tooth wheel opposite each other.


-Mike

 

Thanks Mike.

Should I run crank speed or cam speed with a 12-1 setup?

 

Crank speed, 12-1 has done it for me for many thousands of miles. I've been playing with a fully stock CAS and cannot get rid of a minor but annoying noise problem on 2nd trigger so am probably putting my 12-1 CAS back in later today. Let us know how you progress...

 

Ok thanks for your help. I'll hopefully get a chance to try this on the weekend. Are the rest of my settings ok?

 

I'm interested in how this turned out.

I am having problems with my 2nd VR signal too. I have about 10% ripple imposed on the 2nd VR from the 24 tooth VR. This is even after changing to separate 2-conductor shielded cables, one for each signal. I think it is being created inside the CAS istself.

Thinking of moding the CAS to the missing tooth variety and eliminating the 2nd VR. Any reason not to do this?

 

Finally got around to testing the missing tooth setup and.........it's fantastic! Final settings were: 12-1, crank speed and falling edge.
Had some noise at idle but after adjusting the trim pots a couple of turns it disappeared. Now it revs smoothly and drives with no huge misses that I got with 2 tooth trigger.
Now it's time for some tuning and fix up the staging as it won't rev past 4000 without going very lean. Anyone got any staging parameters that work for 500 primary and 1600 sec with 2.1.0?

 

For 2nd trigger to work, you must set up the second trigger conditioner properly.

Pin 14 on the lm1815 must be grounded, and the G+ and G- wires where they go into the lm1815 circuit should have a .01uF cap across them.

With those two things done, I have never had an issue with dual trigger.

My test CAS on the bench does not show any crosstalk between the two sensors, and neither does the one in my engine.

Ken