I have a 2001 blazer with the 4.3. I bought it not running and after replacing the fuel pump, fuel filter, spark plugs, battery, and distributor cap and rotor I got it running great. After a couple of drives though it got to the point where it would start really rough and I would have to give it gas to get it started. Then a few days later it wouldn’t start at all without jump starting it or spraying ether into the intake. When it did finally start with that it would barely drive. Wouldn’t get above 4k rpm, bogging down, but still idling great. Now it doesn’t start at all no matter what i do. This all happened within a couple weeks so I am confused as to what deteriorated so fast. It is getting good pressure at the valve in the engine bay. I suspect it is still a fuel problem as im getting good spark and the maf is reading good. No codes as well. Could it be injector or fuel pressure regulator? The entire spider system is quite expensive so I want to be sure before I replace it.

 

If it's firing, it should at least pop on ether. The next thing I would do is pull some plugs and see what they look like. Does the gas have water in it?

 

it does start on ether it just doesn’t stay running. It has all new plugs. The gas might be a bit iffy but it ran just fine on that gas before. The fuel that came out of the filter was brown though.

 

The next thing I would do then would be to drain the tank and put fresh gas in. Also get what you can out up at the engine. Remove the fuel line up top and bleed it out. I can't help too much with that because I haven't 'played' with my '02 much. I'm getting there on my TBI '91 though.

 

I tried to short the pump relay in the engine bay to drain the tank that way and now the pump no longer works at all and neither does the fuel gauge.

 

This exceeds my abilities. Check fuse(s) and relay?

 

It was a fuse that was my bad. Tried some stuff today and it will sputter a bit when trying to start after priming the fuel pump a bunch of times.

 

Check the fuel pressure. Sounds like the pump to me. What brand was the new pump you put in?

 

I believe its Hella. Not ac delco I know but should still get the truck running.

 

There is a thread here somewhere with an OP that had to go thru 3 non AC Delco/Delphi fuel pumps to get a good one.

George