Remote Start Woes

I've decided to start a new thread about my install of a Matrix 3.5 rsx into my '89 240sx.  I've been having some weird problems trying to get the remote start to work.  Here's what I've got so far:

1) All wires from the alarm are hooked up correctly.

2) The car is manual, but all corresponding relays and wires (clutch override, neutral safety switch) are working correctly.

3) When I activate the remote start, the alarm brain clicks and the lights flash, but nothing happens. 

4) I then ran a 12v wire directly to the starter, on top of the 12v spliced into the remote start relay, and tried remote starting again.  This time, the engine started turning, but would not fire.

What does this mean?  Am I just not running enough power to the heavy gauge wire realy on my alarm to power the starter? 

I have not cut and attached the RED / white additional 12v input wire on the relay.  Should I just run another 12v there?

Why is the engine not firing?

It's driving me nuts being so close...

it have 2 starter wire on your car

1 BLACK/ white

2 BLACK / YELLOW

1)  I think this might be the problem.  I tapped the tach wire at the ecu, and even after running the learn routine, it still twitches and acts funky.  How exactly does this effect the remote start sequence?  Is it preventing the relay from sending any power to the starter circuit during remote start?  Where/how should I connect to the tach to ensure a clean, strong signal?

2) Yup.  Tested and verified brake light, hood pin, door trigger, neutral safety, etc. with DMM

3) No seperate starter kill module installed

As far as the unit being defective, it doesn't seem too likely, as all the functions are working fine, including those connected to wires in the remote start relay, like the doors lock/unlocking based on ignition.  Like I posted earlier, I've been able to get the eingine to turn after runnning a 12v to the starter, so it seemed like a power issue...  Other than that, I have no way of telling if the unit is defective or not...

Thanks for all your quick responses so far!

Well, I've now got a solid connection to the tach behind the cluster (consistent AC voltage of 3.75 VAC verified with DMM) and the exact same problem remains:

- I f I try to remote start normally, remote start sequence begins, but nothing happens (lights flash, alarm remote shows RS symbol, but engine does not turn)

- If I run a seperate 12V to the starter circuit, and try to remote start, the engine turns, but does not fire.

What is going on???