Quadspark - Odd shorting behavior when mounted to firewall

[Lurker27]

Quick Question - I'm running MS3X out to a quadspark, out to an IGN-6 coil pack (All from DIYAutotune).

With the quadspark sitting on the valve cover, everything is fine and runs smoothly.

With the quadspark mounted to the firewall, I get chugging/misfiring behavior - the car will barely run and is on 4/6 cylinders at best.

What's up with that? Is the heatsink electrically conductive to something inside the case? We did drill out the mounting holes on the heatsink to use bigger self tapping screws to keep it attached, but we'd rather not have it flopping about in the engine bay. The only other thing I can think of is that I need to trace each wire and make sure I'm not getting any external shorts, but I was curious if anyone's ever had this problem.

Obviously no msq needed because it runs fine with the quadspark in nonideal position.

Ryan

[elutionsdesign]

Use an ohm meter to test continuity between your inputs/outputs/grounds and the heatsink to isolate which circuit is causing the problem.

[Matt Cramer]

The heat sink should not be connected to anything. Check the resistance from the heat sink to all four spark outputs. If you measure less than 5K ohms, please contact us directly at websales@diyautotune.com for a warranty replacement.