remote start in 97 altima

A few things I would suggest checking.

1. If you've used the factory hoodpin wire, remove it and install your own hoodpin. I've found that Nissans have all kinds of electrical noise on their hoodpin wire that can randomly shut down most remote starters.

2. Make sure that your ignition harness wires are connected properly - all 6 wires from the ignition switch should be connected, including the cold start wire. Meter them to make sure they all show 12 volts when they should.

All need to be set properly as ignition, acc. or start. Also, if you've got the main starter wire cut for the starter kill relay, the remote starter's start output needs connected on the side facing away from the key switch. 

3. If none of that works - try switching from tach to voltage sensing, or vice versa.