2000 Bravada. Recently, I have been getting Code P0300 multiple engine misfires detected, she would hesitate erratically when driving only at 2000 RPM. If I let the vehicle sit for a couple days without starting it, she would sputter when cranking and eventually start, but running it everyday she would start immediately. Well, she sat and I cranked the engine today and I heard one sputter/pop and that was it, no attempt to start after that. Here's what I checked/did... Fuel pump is priming for a couple seconds upon turning ignition switch on. I checked for spark at No.1 cylinder plug wire and good spark there. All fuses good. I dumped some gas down intake plenum and cranked...nothing, then spayed some starting fluid down it, cranked and got maybe one cylinder attempting to fire then nothing. I don't have fuel pressure tester but would think if there is spark and injectors are not spraying due to low fuel pressure, the engine should of at least made a attempt to fire once highly flammable starting fluid was directly injected. OK, additional info I'm adding that I think is the problem but there is no fix I can find for this one...The security light in the dash stays blinking when a door is opened (key in or out doesn't matter), then goes out when a door is closed! Totally backwards right? I remember normally the light only would blink after close door and lock the vehicle with the key fob and go out after I unlock with it. Now the second the door is opened the light blinks. The frustrating part is I can't reset the security system because when I put key in the "on" position the light goes out! It doesn't stay on! like there is nothing wrong with it. I did try PassKey III reset sequence- it did not work, Also I tried to disconnect the battery for 30 minutes and now every possible idiot light on the dash lights up when I turn the key to the ON position, and security light still blinking.