94 4.3 blazer Runs fine, but only start with either
 

base timing, wire under carpet pulled set at 0 degrees. Vacuum at idle is 17psi, fuel pressure with key on engine off holds at 54psi, when trying to start drops down to 44psi after 5 seconds while turning over. idles at 56psi, when driving it goes between 54-60 psi. Gets 19mpg on the highway and 12 in the city.

Runs great but there is one problem, it has to be started with either. first thing in the morning when its cold or the second you turn it off when its hot, no matter what you need either to start it up. it used to only be a few times a month but these last few weeks its been every single time. now before it started acting like this, when it would start up you couldn't just hold the key, you would have to hold the key for half a second and let go, if you didnt let go it would act like it would start but then just turn over really fast. I would really appreciate any help offered, thanks in advance.

Looks like you have a fuel pressure issue. You need at least 55psi for it to start properly and it shouldn't drop like that while cranking.

Yes, weak fuel pump. My `94 needs 57 psi. or it will not start.

wouldnt it be worse while driving, because i floored it and the fuel pressure stayed above 54 the whole time. or maybe trying to start the vehicle drops the voltage to much for an old fuel pump to work properly?

Fuel pump

I had the exact same problem, it wouldnt start without spraying some starting fluid into it. Turned it off it wouldnt come back on, even though it was hot, etc. But once it was started it ran like a champ, right? I tried everything and finally replaced my fuel pump and now it starts on the very first try like it should.

thanks for the response, i will definitely be replacing the fuel pump now.

Just to let everyone know, it was the fuel pump. The wore out old pump had enough voltage to run the vehicle when the alternator was charging 14.7 V but not enough voltage when trying to start 11 V. Thanks for the help

glad to hear your back up and running again. It took me forever to finally admit it was the fuel pump. I tried everything, new filters, different FPR's, different spyders from the junkyard, replaced the injector harness. etc. Finally got a pump and now it starts like its brand new. Knock on wood.