Hey guys, got a problem with my wifes 2000 blazer 4x4x4. I put a delphi fuel pump in it about a year ago and every sense it has a hard time starting. I put a fuel pressure gauge on it and it seems to be leaking pressure down pretty quickly. I've read on here that it could be the pressure regulator or the spider assembly. Before I put the new pump in it would start right up like it was supposed to. I replaced the pump when it went out at about 130,000 miles. I thought maybe it was the new pump so I exchanged it out. Problem still there. Can anyone help me diagnose this and where to start first? Thanks

 

The leaked down test indicates a problem with the fuel system.What are the numbers?

I cant see two fuel pumps being bad.
Do you have any check engine lights>Has the fuel filter been changed?

 

I can't remember the numbers exactly but it drops off quite a bit. No check engine lights.The filter has been changed when the pump was changed. It has been getting harder to start here lately.It runs fine after it starts.

 

I had the same issue on my 99 Blazer. Turned out to be the pressure regulator.

 

Hey express, is the regulator underneath the upper plenum. I wonder if I should start there.

 

Yes, the reg is inside of the plenum. You can take a flash light and look down the throttle body, if it looks really clean or shows signs of washing and you see goldish color then you know the reg is leaking or the injectors are leaking. Has the mpg been bad?

 

So I need to pull the air intake off and shine a flashlight down the throttle body? Havn't really noticed the gas mileage.I will check that later when she gets home with the flashlight.I will also go to advanced later to check if there is any codes showing.Thanks for the quick reply,I will let you know what I find.

 

Also forgot to mention that when I dropped the tank to do the fuel pump I broke the nipple on the top front of the tank. I think it is fuel return.is it not? I fixed it with a brass fitting that I plugged right into the tank where the plastic one broke. Would this have something to do with it loosing pressure?

 

Yup, just pull the intake and look down it. IIRC , that is just the return line and shouldn't effect pressure

 

Ok, I will check that tommorow. I may even pull the upper intake off to look for leaks.I went to advanced to read codes and nothing came up except for my abs which I have disconnected.I will keep posted.Thanks for help.