MicroSquirt.com read only forum (Jan.15,2018)

I am amazed at how well all my questions get answered on this forum. Thanks guys, and keep up the good work! It's good to know that there is some good info out there! So, now for another question.

MSII v3 board, with v2.3 code

I am using the ignition driver circuit to directly run my coil. My question is if this has enough current capacity for a hot spark. I have this installed on a 2.8L turbo and have had really good luck when I run low boost. The problem is, low boost is no fun. Around 15psi and 4000rpm, the engine starts to miss. At 13psi, no miss anywhere. AF is a steady 12.5:1, so I am thinking it has to be ignition. I tried messing with the dwell settings and had a fair amount of luck.

Max dwell, 5.6ms
Max spark duration, .8ms

Increasing the dwell doesn't do any good, since at high rpm, the dwell HAS to be less than what I already have the max set at. Decreasing the max spark duration allows for more dwell, but seems to be reaching a point where the engine misses because it is too small. I am driving the stock coil ('83 Nissan 280zx turbo) which didn't seem to have any problems with ignition on the stock setup.

Any insights? Thanks a ton!
-jeremy-

Hummm sounds like the problem I'm having with the saturn up top.

Have you tryed reducing the gap about .005?
I was gonna look into getting a DIS-2 from MSD. Installing one for my app and not using the timing retard, the unit acts a power adder for the ignition system.


So you are haveing better luck with a lower spark duration? I had mine set to like 3.5 ms and turned it UP to like 25ms to see what happened. I saw no change though

I have my spark duration set really low ~.8ms worked the best for me. I think that I read somewhere that the ignition circuit is current limited to 7amps. I checked my coil and it should draw 12amps according the the resistance. Everything works great with low boost, but the spark isn't hot enough for high boost. I switched back to using the stock ignitor and the problem went away. I am just triggering it with the megasquirt now, instead of actually driving the coil. Using my amp meter on the direct coil control setup, it pulled 1.5amps at idle. Using the nissan ignitor, it pulled 3.8amps. Seemed like a better way to go for me.

I have my spark duration set really low ~.8ms worked the best for me. I think that I read somewhere that the ignition circuit is current limited to 7amps. I checked my coil and it should draw 12amps according the the resistance. Everything works great with low boost, but the spark isn't hot enough for high boost. I switched back to using the stock ignitor and the problem went away. I am just triggering it with the megasquirt now, instead of actually driving the coil. Using my amp meter on the direct coil control setup, it pulled 1.5amps at idle. Using the nissan ignitor, it pulled 3.8amps. Seemed like a better way to go for me.