mobythevan Posted August 6, 2007 Share Posted August 6, 2007 I noticed over the weekend that my setup just wasn't running as good as it should, then I realized that the tach in megatune is bouncing around. At idle it is mostly at 750-800 then jumps over 1000 and back. Holding the engine closer to 1200rpm and it jumps as high as 2000. I am going to put a scope on it tonight to see what is wrong. I have the circuit set up to use the falling edge of the LSx crank sensor input(according to the hall circuit for v2.2 pcb in msns manuals). The falling edge is evenly spaced, the rising edge is not. I also tried a couple experiments. One used the LSx crank sensor signal through a 1K resistor directly to the processor pin. This should be OK because the crank sensor outputs a 5v square wave. Still got the same results. I also disconnected the alternator just in case, but still the same. It may be a problem with where I have connected 5volt supply and ground for the cranks sensor. When I solve this one I think I am ready to head to the track. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.