Hey there, I just recently bought a 2000 blazer with 95,000 miles on it. Its 4x4, 4.3l, 5sp. But its starting to get a little hard to start, esp after sitting for awhile. I had a CEL a few days ago which was P0174/P0102. I took the MAF apart and cleaned it up. Light went out the next day and truck runs better. But like i said sometimes its just hard to start, I turn the key, hear the pump whine for 2 secs then stop. I did buy a pressure tester, When i turn the key and it does the 2 sec prime, it builds up about 54psi, i start then idle its about the same. Then i drove it and while i was giving it gas it would go up to 60psi. Also when i shut it off it goes up to 60psi, and i kept an eye on it, and it does leak pressure down but pretty slowly (5 psi in 10 mins or so)
Like i said before, i can hear the pump whining and the car runs pretty good (does have a slight hesitation when stepping on the gas) but i hear the pump whining even when the truck is running. Does this sound like a fuel pump about to go? I just replaced the fuel filter today, see if it helps at all. THANKS FOR ANY HELP!!!!

 

possible fuel injection spider unit

 

54PSI is low, it should be 60+psi prior to turning over the engine. This could be the possible cause of your hard start condition. When was the last time you replaced the fuel filter?

 

i replaced the fuel filter just before taking those fuel pressure readings. So I got a new pump today. Figured it was getting weak. Hopefully everything will be squared away after that!!

 

Let us know how it goes.