2010 mazda 3 remote start issue

Hey guys, Just did a 2010 Mazda 3 remote start install (no smartkeyless), it was a very straightforward install on this vehicle. It has only been a few days and I just heard from the customer the car is having problems remote starting in the morning (PA weather - not terribly cold here yet). The vehicle is virtual tached so I am wondering is that is the culprit? The unit is a Compustar CS600S and the bypass is a Fortin. Every time I talk to her and ask her to try and remote start it the car fires up just fine.... making troubleshooting a pain. The morning remote start problem goes like this: The car will ----Crank----Run----Die after two seconds. She said the other afternoon when she tried it the vehicle did the same thing. Whenever I call her to try to troubleshoot it with her everything works magically fine. Do you guys think the culprit may be the tach wire? If not, I am out of ideas and looking at you guys for support. Thanks!

Thanks. That is what I figured but I just wanted to ask you guys first. I switched over to Compustar hoping to utilize their virtual tach feature. The Ultra remote start virtual tachs (in my experience) are horrible. You are right, run the tach wire. Thanks.