Sequencer First attempt in car

[RedRocketRally]

My bad. I dragged my microsquirt tach output conversation into a sequencer thread

I'll give those a shot. I just like software solutions, because I'm a software guy. This in a rally car going on some very rough roads, so the fewer points of failure the better.

[grippo]

If we decide to investigate the tachometer problem, it would be helpful if we can get the Autometer model numbers you all are using.

[krisr]

Mine is a 3903 - 5", 10000rpm with built-in shift light.

Kris

[TheMonkey]

Autometer 1497

[Bruce Bowling]

OK, I contacted Autometer and asked them what signal do they need. They indicate a 0-12V waveform at 50% duty... Its kinda hard to do this with the current tach output because it is also used to trigger the router processor and it needs to be as short as possible to ensure high-speed RPM operation. So let us scratch our heads and come up with a solution for this, it will not affect other testing, we just need to fix this and implement....

- Bruce

[TheMonkey]

Bruce-

before i saw your post here, i tested my tach on the bench with MSII (config for 0 teeth) & jimstim (config for distributor/EDIS). this gives a 50% duty cycle square wave 12v, and it worked perfect.

FYI, the MSD 6AL box tach output is 20% duty cycle 12v square wave. something tells me you already know this though...

[ca434sbc4]

Short update...

I lengthened the cranking pulses and then engine wants to start - goes into WUE then dies. The downside is with it being so lean it blew an intake gasket from previous backfire - so testing is halted until the weekend. I need to fix the vacuum leak first. Also the 1F caps supplier backed out.

Bruce what is the maximum capacitive load the switcher will start up into?

[Bruce Bowling]

Also the 1F caps supplier backed out.

Bruce what is the maximum capacitive load the switcher will start up into?

I have no clue... I assume you are putting the cap on the +12V input side, if you put it there with a beefy series inductance before the cap. This should get you over the dip while the starter engages. You can get these on Ebay pretty inexpensive...

- Bruce

[RedRocketRally]

My Autometer tach is #7597.

Just curious. If y'all investigate the tachometer problem, is it just for the sequencer, or will it go back into the regular microsquirt, too? I've just been following this thread, since grippo pointed it out to me from a thread in the "ignition" section.

[grippo]

My Autometer tach is #7597.

Just curious. If y'all investigate the tachometer problem, is it just for the sequencer, or will it go back into the regular microsquirt, too? I've just been following this thread, since grippo pointed it out to me from a thread in the "ignition" section.

We will try to put it in both. Microsquirt doesn't use that tach output for anything else, so it would be easy to put a longer pulsewidth into microsquirt. With the sequencer we might need to use another output line.