98 Blazer running problem

My sons 98 Blazer starts up, runs a few seconds, then quits. He still has all his electrical when this happens and just recently installed a new Fram air filter. Any ideas as to how to cure this problem? Is it a bad fuel filter or fuel pump?

Check the Mass Air Flow sensor for debris. Try un plugging it and see if the vehicle will run I know this works on some makes.

Can you hook-up a fuel pressure tester to the vehicle to see what the fuel pressure is and if it is leaking down.

Let us know.

What engine and mileage?
Any repair work done lately?
Any aftermarket remote start or anti theft stuff?
Has the check engine light been on?
What is the security light doing?
Coming on key on and then going off or staying on?
Is security or anti theft system shuts down engine will start and run 2 seconds and then shut down by turning off injector pulse.
Check for lose of fuel pressure and spark and injector pulse when it quits.

The motor is the 4.3 and we found out after my son bought the car that it had a junk title. The security light does stay on so he is going to try to get it turned off. I'll let you know if that was it.

I think you just answered your question.....If the security light is staying on when you try to start the truck, the truck will not start. The security feature is suppose to cut off or disable the fuel system if it senses an improper key in the ignition etc.

I don't remember the sequence, I have to look for it, or someone on here may chime in, but its like hey on engine off for ten minutes, off and again key on engine off for another 10 turn off and should start. Its the learning procedure your after...I have to find out and verify what I told you.