2003 Blazer, 4.3 4wd, 100000.00 miles
You can hear fuel pump run when key turned, I checked for codes and found none, has new fuel pump and filter about 1 year ago.
I disconnected neg batt cable for several minutes and made no difference
Will start and stay running if fuel poured down throttle body, is hard to start but will restart during the day. After it sits overnight will not restart without fuel in the throttle body again. Does not seem to have power issues or running problems once started. Any ideas, and is there a good manuak I can buy to help with trouble shooting?

 

Do a fuel pressure test and let us know the results. Let this site be your manual. Check out the Tech Article (DIY) section.

 

Yep, here's a post that might help you.

 

Thanks for the help, I'll have to run to the parts store Friday and get a pressure gage. Anything else I should check

 

Probably not until we get the results of the pressure test.

 

I read the attachment on how to test the fuel pressure and I think I am going to have to wait awhile to test it. I just had shoulder surgery about 9 days ago and just can't do it one handed. I'll let you guys know when I get it done.

 

That's what beer and friends are for. 1 friend, 6 beers, all the help you need LOL.

 

I had that problem once and couldn't figure it out untill I changed the Oxygen sensor. Started on it's own every time after I changed it. The Blazer I own is a 92 so it may not be a similar situation. Also there were no codes present.

 

OK I finally can test the fuel pressure and have 42 psi at the valve at the back of the intake manafold. Any ideas, or should I just start dropping the tank and replace the pump that is only two years old? Has anyone ever just cut a hole in the rear deck floor to gain access to the pump?

The pressure go ups to 42 as soon as the key is turned and seems to hold the pressure, How about an inline electric pump?

 

42psi is definitely not enough. You need 60+ psi for everything to work properly. I would not try an inline pump. Get an AC Delco or Delphi intank OE pump and be done with it.