3 bad fuel pumps in a row, unbelievable!

[Korn]

I have a 98 yukon, about 3 years ago I installed a napa brand fuel pump, it worked for about 2 years. I also did the updated electrical connector that came with the napa pump. About a year ago I installed an Airtex pump and it works fine but my fuel gauge vibrates with it so I am guessing that the sending unit on it is kinda messed up, also it would lose its prime after sitting about 4 days.

Here about a week ago I decided to install an Acdelco fuel pump, I got it installed and it would only build up to about 48 pounds of fuel pressure and after about 2 minutes of on/off cranking it finally started and seemed to run fine. Then I shut it off and it lost all its prime in about 15 minutes. I then took it back and got a Bosh pump made by delphi, installed it and it only had about 30 pounds of pressure and wouldnt even come close to starting it. I took it out and went back to the parts store and got another Acdelco pump. Installed it and it wouldnt start it either, it had about 50 pounds of pressure.

So finally frustrated as hell I put the Airtex pump back in and it fired rite up and has about 56 pounds of pressure. Is this a coinsidence of a bad line of pumps or am I doing something wrong. The Airtex pump works fine its just after about 4 days it looses it prime and you have to crank it a bit to get it to fire up. Any ideas on this????????????????????

Before I forget, all 3 pumps worked, and by this I mean that I could here them working.

 

[sumo]

id say problem is elsewhere, Like a clogged fuel filter, or a constricted hose

 

[Korn]

id say problem is elsewhere, Like a clogged fuel filter, or a constricted hose

Cant be I guess, the fuel filter is new and the lines snap rite on. Im not sure if its a plugged line cause the old airtex pump pumps up just fine and she runs just fine with it. I have also had the fuel regulator replaced. I know fuel is getting to the injectors cause I am getting some out of my fuel gauge hose when I go to relieve the pressure. Its just not building up enough pressure like the old pump does. The electrical connecor plugs rite in and you can here all the pumps running as is building up pressure. Im not an expert mechanic but Im pretty sure I got it all rite but Ive messed up before.

 

[sumo]

possible filter Installed backwards. A leaking check valve in the return line that can bleed off fuel pressure causing similar symptoms or leaking injector also bleeding off pressure

 

[Korn]

possible filter Installed backwards. A leaking check valve in the return line that can bleed off fuel pressure causing similar symptoms or leaking injector also bleeding off pressure

Thanks for the tip, I just ran out to the garage and looked and the fuel filter is installed correctly. It just makes me wonder why the old Airtex one works fine and none of the higher brand pumps wont work. Heck Airtex is a lower end pump, it should fail long before the top brands like Acdelco, delphi and bosh. As for the return line, would it made a difference on the pumps? Where in the return line is the check valve? Im really going to hate going back to the parts store tomorow and telling him that the new pumps are bad, maybe I'll send my wife back with them.

 

[sumo]

curious if you turn the key on, off then back on, will it fire right up? How about if you remove the airfilter can you smell strong odor of gas? Could back the idea of a leaking injector

 

[Korn]

Yep I tried the on/off key thing. All the pumps would made noise like there were working for about 2 to 3 seconds, enough to build up a little pressure. I even released the pressure through my pressure gauge to let it build up again. Still nothing, I then did the key on/off thing again, I had my wife cycle the key while I wathced the gauge. I even had her try to start it while I watched the gauge and still none of them built enough pressure. The one pump did but it took a while to get it started. Once it was started it would run fine, let it sit for about 15 minutes and all the pressure was gone on the gauge and it was hard to start again.

I did do the air cleaner trick last week, someone else suggested it at work, and there is no gas smell.

---------- Post added at 08:39 PM ---------- Previous post was at 08:11 PM ----------

I just wonder if its nothing else that could be wrong is it that Delphi may have a run of bad pumps. Cause from what I understand Delphi makes the pumps for Bosh and Acdelco.

 

[SunlitComet]

Have you thought that something may be wrong with your regulator on the fuel spider or the whole unit itself. Would you like some test procedures on that? And just stick with the ACDelco only.

 

[Korn]

I will take any and all help to figure this thing out. I will try your test procedure, what ya got!

 

[retorq]

I just went thru replacing a pump in my 95 4 door, what a pain in the ass. First it only had 5lbs of pressure. I swapped the pump and when I got it all back together it didn't have ANY pressure. After some trouble shooting I found that the pump wiring only had 8 volts. :O Perhaps you are having a voltage issue ...