I changed the throttle body and thermostat and now it wont start. the motor turns but it sounds like its not getting fuel.... the green security key has not stopped flashing and i am wondering if this is the factory starter kill? Plz help

 

Look for wires you forgot to re-connect?
Cluster of ground wires near the thermostat housing?

Check for spark.
Spray TB cleaner into the TB & see if it fires up for a couple seconds.

 

the security key light is still flashing how can i shut that off?

 

Not sure how that would be related to the thermostat. I thought that system was just between the ECU and the RFID antenna at the ignition switch. Did you do anything around the steering column? Center console where the ECU lives?

 

no but when i disconnected the battery terminal i dont think i did it in the right sequence..

 

Explain that a little more. The only thing I can think of is shorting something & blowing fuses. Your '98 has fuses all over the place. Fusebox in the engine compartment. Additional ones in BOTH ends of the dashboard, alongside the door hinges.

 

What did you swap in? If you got new keys or an ECU, they need to be programmed to match each other. The security light is saying that you do not have the proper key matched to the computer and it will not start.

 

Throttle body & thermostat have nothng to do with the immobilizer.

If the engine & ECU were just swapped, that's an entirely different story.