04 f350 diesel tach problems with 454t

I'm installing an Avital 4103 in a 2004 Ford F350 diesel 6.0L. I used the DEI 454t for tach signal. It programmed fine and when i went to remote start it would not crank at all. I went over all my power connections and when i switched it to virtual tach it cranked. I haven't had much luck with the virtual tach so i always run a tach wire. I tried to fool around with the 454t settings and it still would not crank. What prevents the 4103 from cranking over with the 454t programmed to tach? I have never seen this before. I have done 2 of these type installs with diesel fords before and they worked great. I will try the GREEN / WHITE tach wire but from reading other posts that doesn't always work either.

On diesel vehicles the tach wire is GREEN / WHITE in a 5 wire harness held up with white tape behind the parking brake release. The tach wire on these vehicles may generate an unclean signal. Options maybe to set the threshold jumper to “on/low“ when programming tach Or go straight to the ignition coil.Gary Sather