Trigger angle question

[dmeyers]

Quick question, I am running fuel and spark control through MS1extra, should the middle light (IRQ trigger) be on from 20 degrees BTDC until I reach my trigger angle, or should it just briefly turn on for maybe 2-3 degrees? I could have sworn it was on from 20-trigger angle before, now it is the latter case and the engine will not start. Thank you for the help.

[Matt Cramer]

What sort of sensor are you using? Can you post your MSQ? The behavior will depend on your settings and sensor type.

[dmeyers]

I have a 280zx built up following the writeup: http://www.diyautotune.com/tech_article ... bo_new.htm. The sensor is either Hall/optical not sure which (I would assume hall). It is an 82-83 280zx turbo distributor. I cannot get my MSQ file right now, but my spark settings are: Trigger angle 70 degrees, 0 addition, Time-based, cranking advance angle: 5, hold ignition: 0, spark output inverted: Yes, Fixed angle: -10, and trim angle: 0. Set the timing via: http://www.msextra.com/doc/ms1extra/Diz ... ext_6.html. I had a friend run the starter to check the cranking timing with a T light, which showed the proper timing during cranking. I disconnected power to the coil but left everything else connected while testing trigger angle. The IRQ trigger light comes on for maybe 2-3 degrees and then the top light (spark outputA) comes on with it for maybe 1 degree. This seems wrong as it shouldn't fire until it reaches 10 degrees BTDC during cranking, but I am not sure.

I plan on getting into tomorrow, will get a copy of my MSQ and run a datalog of me trying to start it and post that as well. I was just hoping this would be an obvious problem like resistor A is not connected right, etc. Thank you for the help.

[dmeyers]

Attached msq and log of me trying to start it. Sounds like there is some ignition events but never like a compressed explosion, more like a burn with an open valve.

[Matt Cramer]

With that setup, you'd get a very short blink on the middle LED at the point where the optical sensor is lined up with the hole in the disc. I'd check the timing at this point and make sure it's correct.

[dmeyers]

Thank you Matt, will double check everything with the timing.