GM HEI 4 PIN--No Tach Signal

[jimmyv65]

2016-10-25_18.54.57.msl

2016-10-25_18.54.10.msq

Sorry for something so basic, but I am stumped.

I am doing a fuel only set up on MS2 v3.57. I have a GM 4 pin HEI unit. I have the shielded ignition wire (white wire) connected to the TACH terminal on the distributor. I did NOT ground the shield or the black wire at the dist end and I don't have any plug wires close. The motor is a Ford 4.1L with a DUI disty. It ran fine on carb and I pulled tach signal from the same spot on the disty before mega.

Details:
-My megasquirt and harnes are from DIYAutotune
-I tone tested the 24 wire and it was fine from the plug for the HEI to the plug for the ECU
-Hooked up to the stimulator, I see an RPM/Tach Signal
-Hooked up to my motor wire harness:
--No RPM/Tach signal
--Signal from all my other sensors.
--Getting spark. It will fire if I put some starter fluid down the pipe, so I really know I am seeing spark.
--Validated the jumpers on the board per this:
V3.57 Opto-isolator (for coil negative fuel-only triggering):
a) Find JP1 in the bottom right of the board. Place a jumper across positions 2 and 3
b) Find J1 in the middle of the board. Place a jumper across positions 1 and 2
c) Place a jumper from XG1 to XG2 (just to the left of J1 above U3.) In exceptionally noisy situations it might be required to remove that jumper and instead runs XG1 out through a spare connection on the DB37 and through the loom direct to the engine.

[Matt Cramer]

Make sure your tach input pin is connected to the negative terminal of the coil.