Sounds like a vats problem to me. While the resistor trick works on about 95% of vats problems, it would seem you fall into the 5% category where it doesn't.
So before we go to the next step, let's make sure you measured the resistance of your old key correctly and put the correct resistor value in. shbox.com has a good write up on vats and a chart there which lists the 15 correct resistance ranges that GM used in these cars. Does your resistor value match one of the 15 on the chart. If no, correct resistors to the right value. If yes, lets move on
One final note, bypassing the starter relay by putting the large yellow and purple wire together is not the best way to get starter to work. This is why. By doing that you have disabled the safety system designed in that won't let car start in gear. With automatic trans in your car, it will no start with gear selector in any position, or if manual, without the clutch pedal being pushed down.
A better way to bypass the starter relay is to cut the small wire on the relay, it's the only small wire there. It's yellow/black on earlier models, not sure about 96, however. Splice in a piece of wire a run it to a good ground. Now, if relay and wiring are good, starter will crank engine, and safety interlock will be in place.
Next you need to go to Baker Electronix - GM VATS Bypass there you will find the 50 hertz vats bypass module. What this module does is send the 50 hertz fuel enable signal to the pcm, so pcm will open the fuel injectors. When you hook it up, you provide it with power, ground, then cut the wire that goes from bcm to pcm and splice the module wire into the original wire going to pcm.
Now every time you turn ignition key on, pcm will be getting fuel enable signal so pcm will open the injectors.
So before we go to the next step, let's make sure you measured the resistance of your old key correctly and put the correct resistor value in. shbox.com has a good write up on vats and a chart there which lists the 15 correct resistance ranges that GM used in these cars. Does your resistor value match one of the 15 on the chart. If no, correct resistors to the right value. If yes, lets move on
One final note, bypassing the starter relay by putting the large yellow and purple wire together is not the best way to get starter to work. This is why. By doing that you have disabled the safety system designed in that won't let car start in gear. With automatic trans in your car, it will no start with gear selector in any position, or if manual, without the clutch pedal being pushed down.
A better way to bypass the starter relay is to cut the small wire on the relay, it's the only small wire there. It's yellow/black on earlier models, not sure about 96, however. Splice in a piece of wire a run it to a good ground. Now, if relay and wiring are good, starter will crank engine, and safety interlock will be in place.
Next you need to go to Baker Electronix - GM VATS Bypass there you will find the 50 hertz vats bypass module. What this module does is send the 50 hertz fuel enable signal to the pcm, so pcm will open the fuel injectors. When you hook it up, you provide it with power, ground, then cut the wire that goes from bcm to pcm and splice the module wire into the original wire going to pcm.
Now every time you turn ignition key on, pcm will be getting fuel enable signal so pcm will open the injectors.