Viper remote start wont work

I have got a 1999 Chevy Suburban and I just put in a Viper 751 Remote Start/alarm. The system is completely installed and everything works except for the remote start. We have all the wires attached and have gone over every connection and instuctions at least 10 times. When you press the remote start button the system will work fine, the starter will go and it will atempt to start but will die instantantainiously. I know what you are thinking, you have to bypass the passlock II. Done that. We got the GM 555L bypass module and installed it. But nothing has changed from before we put it in. The system will give three atempts at starting the truck and will stop. And also, shouldnt the passlock lock the ignition after 3 failed attemts to start the vehicle without a key, just wondering because it hasnt locked up after numerous attempts. We even disconected the battery and let it sit for a few minutes to reset the system. Every connection is perfect and everything should work, BUT IT DOESNT! Any suggestions or similar occurances with anybody else? Also we cannot seem to get the system to learn the tach speed. We hooked it up to the wire that reads 4.83 volts when running that is located behind the instrament panel. Started the vehicle and held the valet button down within 5 seconds, I must have held that stupid valet button for 5 minutes and never got the led to light up signaling it learned the tach. The books only advise to this is check to make sure the led and valet wires are pluged in to the correct slots. What should I do to find the tack wire and could this be a cause of the remote start system not working. Thanks a lot, and I would appreciate any reponse.