new battery,altnator,starter,changed all fluids and still not start. but it will turn over.acts like its not getting spark or maybe fuel but i hear the fuel pump kick on but still nothing. and also just replaced the ecm computer module too and still nothing need help asap thanks.
No
You need to replaced the starter or the alternator.
battery may not be the problem check your starter motor and ignition switch
Your 2000 GMC Sierra Vortec might be hard to start because the battery or the starter are worn or dead. The GMC Sierra might also be hard to start because of a clogged fuel filter.
Weak battery Bad starter Loose or corroded battery cables Bad neutral switch
Battery cable connections may not be tight. The starter could be bad. The starter solenoid could be bad. Check to see if the lights work. If they do, leave them on and try to start the vehicle. IF the lights dim, you have a bad battery connection somewhere or a bad starter.
the starter motor needs replacing
is your battery in good condition and fully charged? is your starter good?
If the car will not start after replacing the battery, then the battery was not the problem. If it will not turn over, you may have a bad starter or bad connection. If it turns over but will not start you either have no fuel or no spark. You will have to determine which.
Diagnosis: Engine Won't Start or Run Check related link below
There is no battery in the starter.
Starter won't crank over engine? Battery or battery connection issues. Starter cranks over engine but engine won't start? Being a GM product I would suspect fuel delivery problems (bad fuel pump).