Need some help. My engine will not start once it is hot. Starts fine when cold and drives well. However, once it reaches normal op temps (180-200) it will not re-start. After working with Joe at MSD tech, he told me to run a wire from the yellow wire of the throttle body to my Auto-meter tach; he said this will show if the ECU is sending a tach signal to the ignition box. When cold, the tach shows around 130 RM but when hot- NOTHING. Therefore, we have determined that the ECU is not sending a signal to the box when hot. I did send the entire system, ECU, computer, and hand held back to MSD and the supposedly fixed it (but I am having same problems).

My general set up is as follows:
351W
Mild cam
in tank pump
ignition timing run through MSD Atomic efi (MSD dizzy locked out, etc)

I have gone through all the spark tests and everything works as it should EXCEPT the yellow wire does not send a signal to the tach when engine is war,

About to dump the entire system (or at least get rid of the timing feature) unless I can figure this out.