When I go to start my Blazer, it cranks, but it would either stay started for a second or two, or just crank and not start. I replaced the fuel pump, fuel filter, and relay recently, so I'm thinking it could be one of those, or something with the distributor cap and rotor, which is a pain to access. Any thoughts as to what it could be?

 

FYI - It stays started now, for some reason. I'll let it sit for an hour or two and see what happens.

 

Similar problem with my 02. Went crazy and changed the ignition switch first thing. Then signed up and read most here say ck fuel pressure first. Mine worked for a while, but wife just called and said it's dead in the driveway.

 

What brand of parts are you using. If you didn't use Delphi or AC Delco then thats likely your issue. Even when brand new the off brands are usually junk. Yes the easiest place to start is with a pressure check. Its been covered a ton on here so I'm not going to go into it but do that and let us know the results.

 

Had the exact same problem with my 99. Turned out to be the passlock system. If the alarm thinks somebody is stealing the car, it will kill the fuel supply. When you turn the key, it primes for 3 seconds regardless, that is why it lets it fire up, but when the priming is over the pump shuts off and the engine dies. If you let it prime and try to start, it will just crank and not start.

My problem was just I had to wait 10-15 minutes for the system to disarm/reset. If it doesn't do it again (you may do a fuel pressure check just for peace of mind), I wouldn't worry about it. If it does do it again, wait about 15 minutes and try it. If it starts, I bet the system somehow got tripped. However, I have heard of people having problems with the key switch messing up the passlock too.

Not to say its not mechanical/electrical, just my experience.