Car Starter Install trouble

I recently purchased a Predator 4001 Auto Car starter from future shop and I am having some trouble with the installation.

The vehicle will not let me set the tach rpm's during programming.  Possibly because of this the car will turn over but not start.  I have a 1991 Chevy Lumina.  Everything else is working as far as locks, lights etc. 

The input for the tach is measuring properly as I have tried the white wire and the purple white wire.

Is there any reason why the car will not let me set the RPm's from the tach.

Any help would be appreciated

Thanks  

Thanks guys for the suggestions.

I am at the point now where the car will turn over and start but I have yet to accomplish the rpm learning.

This particular auto starter has come with a signal booster for the tach wire to amplify and clean up noisy signals.  Has anyone ever installed one of these or know's if this could cause some trouble when trying to memorize the RPM's.  At this time I still have not moved the tach wire to an injector because of the weather outside (we have the snow already...Barrie, Ontario).

I will try the other two wires again maybe without the amplifier and see what happens.  I will keep everyone posted.

Thanks again

Update,

I found that removing the tach amplifier that came with the unit, made the tach memorizing possible.  The car now starts properly!

Thanks for everyone's help and I hope this information helped others.

Adrian

P.S.  I used the PURPLE / white wire!