Yes it is KMT. There is a test for the VMMM and it fails step one - no tach input. No further tests can be ran with out the tach input. I have been wire checking for continuity and grounds - found nothing wrong yet, including the tach input to the VMMM.
Doug, I have been fighting this problem since 2004. At first it would go into limp home mode. (two cylinders & tack working)) It seem to be the DIS. I have replaced many of them over the years. Now it bucks, tach intermittent and dies. (2013-2016) I can get it started, no tach & CEL on to get it home.
I just replaced the main forward harness, (thanks KMT) DIS, Cam & Crank sensors with parts from Super Coupe Performance in February. It died on the way home. (about 7-8 miles) I did mange to get it home and have been working on ever since. I even changed EEC's. (good second computer) No help.
I do have a new coil coming today and will try that. If that fails, I'm going to try the DIS that KMT sent me. You never know. Maybe another DIS from NAPA, that fixed everything in 2016, till December of last year when it started to die again.