Ok guys, I've done a lot of searching around the forum today and I'm pretty sure I have my problem narrowed down to a bad pump. For about a year now I have needed to let the pump run for about 3 seconds before starting or it would need to crank for 10 seconds before it started.

I think the pump finally went because I don't hear the pump kick on when I turn the key and it won't start at all. I know ACDelco/Delphi is the way to go for pumps and I am planning on doing the work myself. I just want to make sure I am getting the right part, these things aren't cheap. On Amazon I am seeing Delphi "FG0052/ FG0072" Electric fuel pumps for around $250. I know the difference between the two is that one includes the new strainer which I need.

But I am also seeing fuel pump replacement kits that just include an ACDelco pump and hoses for much cheaper. Is it possible to rebuild a pump?

Lastly, on Amazon I also see a Delphi "Fuel Pump Assembly" for $370 and the picture seems to include hoses that the pumps I mentioned above don't seem to include according to the pictures. Is there a difference between getting the pump only and getting the whole assembly?

Thanks for the help. This forum has been great for me in the past. I feel like this truck is a never-ending series of problems.

 

You might want to check rockauto.com, I saw them yesterday for under 100 bucks.

 

You might want to check ebay first !! I bought one for my 97 blazer 4dr for $162 shipped !! It came complete with everything !!! It should be going in this week!!!Yes it is an Ac/Delco

 

I ordered an AC Delco through amazon for $180. Hopefully it is the real deal and will come as the complete assembly. Will pick up a new strainer from a local shop. I'm hoping the install goes smoothly

 

Which fuel tank do you have? If it's the plastic tank (RPO code NE2) then the FG0052 Is the pump you want. If not then It's a different pump. I'm not sure what the differences are but I know they're different between the Steel and Plastic tanks, and also different between the 2 and 4 door models

 

Well I ordered an AC Delco MU1755. It said it fit the 2001 2 Door model so it should be right...or so I'm hoping

 

Well before putting the truck up on the lift we checked the relay and changed it out. Boom the fuel pump worked. So that was easy. But I still have a problem.

I hooked up a pressure gauge to the test port up front, and when the key is turned the pressure jumps to 62 but falls to 0 within 10-15 seconds. When the truck is running it holds at 57. It starts up and runs with zero problems, full power on acceleration so I know the pump is working. But I know you're only supposed to see a pressure drop of less than 5psi within 10 minutes after the pump runs.

So my question is, am I experiencing a blown check valve on the pump? And if so, is it worth replacing the whole pump just for this problem? I have a hard time spending that kind of money and time on replacing a pump when the truck starts/runs fine.

 

well it might be a failing FPR. might wanna pull your intake apart and check that before dropping the tank. I just did mine and it only took about 30 mins to pull it apart. otherwise disconnect the fuel line by the filter adn fab up an adapter to plug your test gauge in there and see if your holding pressure at that point. this will show you if your issue is in the tank or in the intake.

do what I did, buy a new filter (decent idea for preventative maintenance right?) and take it and your gauge to a hardware or plumbing shop. they can help you find and needed fittings to attach the two. I think I spent about 10 bucks to get all I needed, just cant remember what they were and they are not here right now... then swap in the new filter with teh gauge on it and test away. once your done you just leave in the new filter.

 

Get yourself (or make it) a test fixture, to figure out if it's the pump or the pressure regulator.
I had a hole in the gas line that leads from the pump to the top of the pump housing, giving a reading similar to what you list.
With this tool, you place a shut-off valve after the fuel filter. When the pump is energized fully, close the valve to check if the fuel regulator holds pressure. If pressure holds, regulator is good. Turn the key to on (not started), let pump energize, turn key off with valve open. If pressure drops, it's the internal pump assembly leaking.

Thanks to a write-up Captain Hook e-mailed me, I made a gauge to check the pump pressure.

The gauge was made with parts readily available from Napa and Ace Hardware.
Napa 730-5013 steel fuel line repair fitting, 3/8"
1 ft 3/8" hose, 2 clamps.
Ace - 3/8" ball valve
3/8" male to barb fitting (for the hose attachment)
3/8+ male/female adaptor (because the steel tube hit the ball of the valve)
Captain Hook's parts were somewhat different, but close to the valve (lower unit in the picture above). I clamped the open end of the hose onto the output of the fuel filter, and steel tube into the pipe to the injectors.
Once the fuel pump primed, I shut the valve as soon as the pump stopped.
Pressure gauge registered 52 psi steadily. As soon as the valve was opened, the gas went back thru the pump, and pressure went to 0 immediately.

About $20-30 to make the shut off valve. Cheap Insurance before buying an injector assemby (~$450) or a new pump assembly($300+)

 

I forgot to mention...we lifted the truck and hooked the gauge in behind the fuel filter...could not register a pressure at all even when the pump kicked on/truck was started etc. Don't know if we were doing something wrong but it's kind of a simple procedure to tie the gauge into the line (we had the correct fitting, nothing homemade) so we were stumped. Made no sense that the fuel supply line had no pressure at the filter when we were getting a reading of 62 up at the test port on the same line.