My 2000 GMC Sierra has a problem starting.. it turns over like it wants to fire up ..but like the fuel is not getting to it..to turn over... on occasion it will fire up and run good.. but then other times will just not fire up... can it be the module in the ignition not sending the signal to the fuel pump... something to do with the security system? Also when left sitting for a few days...the battery goes totally dead.

Bruce Bracey

• 1000 Answers
• Posted on Apr 30, 2009

SOURCE: 99 GMC Sierra Pickup: Crank but no start. starts

The theft light issue is a good observation. Have you replaced the key tumbler or an ignition component lately? Has there been a lightning storm close very recently?

What the flashing security light is indicating is an attempt to relearn the key you are using.
Turn the key to run position, allow light to flash for 10 minutes, when light stops flashing turn ignition to OFF position for 5 seconds, turn ignition to run position and start over. Do this for 3 consecutive cycles, the the theft system will relearn the key cylinder code and store it once again.
Try that first before you go any further.
Let me know what you find.
Regards,

SOURCE: fuel pump- 2002 GMC Sierra

The fuel sending unit only controls the gas guage not the fuel supply to the vehicle. The pump is twelve volts. If you are not getting twelve volts on the PUMP wires check the fuel pump relay and the key circuit to it. If you have to cycle the key three to four times rapidly to get the vehicle to start check the fuel pump pressure at the regulator for manufacturer specs. An injector stuck open will also cause same problems you are describing.

SOURCE: my 92 gmc sierra ran

Happens all the time with 70's 80's and 90's GMC trucks. Replace the control module in the distributor cap.

SOURCE: 1995 GMC Sierra 5.7 liter stalls and is hard

even though parts are new they also come with defects so it sounds as if when you turn the key you hear it working and other times not at all hmmm connections are tight ? could be faulty fuel pump or relay .

SOURCE: 1997 gmc sierra pu.5.7L won't start in cooler

you need to have the engine coolant switch checked,since the computer relies solely on sensors,the ect tells the computer how cold or hot it is so the computer will make it a rich or lean mixture to start the engine,if it tells the computer that it is 75 degrees the computer will lean the mixture like starting a car in the winter without a choke.