Vitals: 2000 Blazer, 4.3l, 4x4, 121,000 miles.

Problem: When I go to start the car it will start but immediately die. It starts immediately like you'd expect but shuts off just as fast, almost like I'm turning the key off (which I stupidly told my wife she was doing when this first happened a few weeks ago).I can hear the fuel pump run up to pressure and shut off. It started up and ran just fine this morning. I haven't scanned it yet.

Any ideas?

 

Let's start by checking the fuel pressue. The directions are here in this thread.

 

Have you noticed the security light coming on at all?

 

It sounds like the symptoms of a chipped key not being used to start the vehicle!! Hence what kyle said.

 

yeah chipped key what gr81 said....didnt really need to post this though...

 

It would appear to be a problem with the Passlock system.

Probably because your key isn't chipped. Or your ignition switch has failed (mine is in process...does this every so often..pretty much whenever I'm in a hurry).

 

I was trying to rule something out on that!! My 99 nissan maxima was like that if I tried using the spare key without the chip in it!! Also I drew a blank on the name of the system you mentioned(passlock system) that is more likely what is happening in this case!!

 

Gee thanks for reiterating what I said... Too bad - no chip... We really need the OP to respond before speculating further.

 

I thought maybe the thread had started a life of its own!

OK: Check fuel pressure - 60.1 lbs when the pump goes off. No leakdown to speak of.

No chip in this system....plain old fashioned key. The ignition switch idea has merit. My 55 had that issue once.

It has started and ran fine ever since the last episode.

 

Have you noticed the 'Security' light coming on at odd times or staying illuminated after you attempt to start the truck? If so, I would definitely say that you have a problem with the ignition switch. This kind of problem can come and go, potentially leaving you stranded in the most inopportune time.