I have a 2002 Blazer 4dr 4wd 4.3L auto trans, it was run out of gas once and has been trouble ever since. I have replaced plugs, wires, cap, rotor, fuel filter, fuel pressure regulator, and fuel pump, and it now refuses to run... after I replaced the regulator and decided it was the pump it sat for about 3 to 4 months before I was able to budget a fuel pump in, it would run to an extent after I cycled the key about a dozen times but had low pressure when I did the fuel pressure test so I parked it because it wouldnt get out of its own way. I have acquired a fuel pump and installed it tonight and it still refuses to run. When it was sitting I could get it to start and idle but that was it until the battery went completly dead once and have never got it to start again just figured the old pump had kicked the bucket. As it sits now it has spark and is gettin fuel i think but not 100% sure, it sputters like it wants to start but no go. I am planning on gettin a fuel pressure gauge tomarrow and givin it a try the one I used tonight we could get to work if we gently blew air in it but would read 0 when we put it on the blazer, but not that it means much it does spray fuel out of the schrader port when you push the thing in the middle in.Also goin to try putting some noid lights on the injectors to make sure they are firing correctly. Is it possible to get the return and fuel supply lines switched around on the pump. Also we tried puttin a little gas in the intake and it would not start on that. But in the meantime thanks for reading my short rambling book and if anybody has any suggestions I would greatly apperciate it.
Also Iforgot to mention I left my brother and friend alone while I ran to town when we were takin the tank out andmy brotherbroke the little vent on the front of the tank, what problems will this cause?

Brian

 

One thought is that the battery being low is not allowing the pump to build up the required pressure or provide the required spark to get it running. Fully charge the battery and then let the pump prime a couple of times before you try to start it.

 

I have since charged the battery and put a battery maintainer on it, to avoid that problem and to keep the battery from freezing. After it sat in my friend's heated garage overnight he went out and hit the key and got it to start. It started hard and idled fine just ran rough when he wound the engine up. So I replaced the fuel filter again and now it runs like a champ. When I hit the key it makes like a half a turn of the starter and is purring like a kitten. But thanks fnirish for the suggestion.

Brian