Ok, I've been reading through various posts here over the last several weeks and I'm pretty much to the conclusion that my fuel pump is going bad. It all started when one day my car would not start. It's a 2001 Blazer 2WD with 150,310 miles and it's a 4 door if that matters. Never had any mechanical problems at all and it's been in the family since brand new. Anyway, I managed to get it started by banging on the gas tank while someone else tried starting it. Since the gas tank was basically on empty I immediately went and filled up with premium. Everything seemed fine for a few days then it wouldn't start again. I changed the fuel filter but I still had to bang the tank with a rubber mallet to get it to start. Over the next several weeks it would randomly not start and I got in the habit of carrying the mallet in the backseat as my backup key. Now I was driving it home and it died at least 3 times while cruising at 55 mph. I'm to the point now that I just parked it in the driveway and carpool with my wife until I can figure out what to do and have the money to do it. I also checked the relay and that was fine. My question is do I need to finally replace the fuel pump AND should I buy only a particular brand? I called Autozone and they said they had one for $162 and I've seen online autoparts stores sell them as low as $67. They both claim to be OE replacements, is this different than OEM? Any help would greatly be appreciated. One more note, I called a local mechanic shop (Christian Brothers) and they said it would cost around $900 to replace the fuel pump but I have a friend of a friend that works at a large Chevy dealership in my area that said he would do it for $100 labor so I have no problem spending the extra money on the best pump.
Thanks,
Shaun

One more note, it's been sitting for a few weeks because it wouldn't start but I went out and banged the tank and it started up after a few tries. I drove around the block and back home. Parked it and it's started back up at least 5 times just fine. Is this for sure the fuel pump? If so, why does it just randomely do this and will it eventually stop working all together even with the banging on the tank? I'm just trying to get by as long as I can without having to replace it because money is beyond tight at the moment. Also, with the mileage is there anything else I should have done if and when I take it in to get the pump replaced? Like I said previously, theres never really been anything done to the car other than fluid changes.
Thanks.

 

Went through this with 2 different blazers. I invested in a fuel test gauge that screws right onto the fuel rail on the back of the manifold.
You can go two ways. You can parts replace or you can troubleshoot using the guides here.
I'll just tell you about buying and replacing. you figure out what you want to do.
I bought one from ebay 3 weeks ago. 120.00. Thought it was direct replacement. I had to cut some wires and splice in THEIR plug. NP. I called them to make sure. Tech support helpful.
Replaced the pump. Within 20 mins I had a EGR cel that I still have not fixed. The car now hesitates and I also replaced the fuel filter twice. BTW, the gauge did not go up to the full mark. It was 1/8 tank short.
I called, they sent me a new pump no charge without me having to pay. Also emailed a UPS return label.
New pump arrives. It doesn't need the splice. It is an EXACT replacement. So now I have to unsplice.
I also am throwing codes for EVAP pressure loss. In my reading, the seal may be leaking. Maybe my fault. I'll check and correct that when I replace the pump,,, AGAIN.
My pressures are 63psi and never drop below 58. It holds the 5 and 10 minute test.

So there you go. Pick your road. GM or aftermarket. Parts replace or test the system.

Last word. On my 96blazer I went GM. Never had a second of trouble with it. The above is my 2000.
The job is not bad. Certainly worth saving 900 by putting someone's pump on there.
I should add that there were NO issues with the blazer except for the gauge not working. No running issues at all. no codes. ZIP, NADA, ZILCH. I only replaced to fix the gauge issue not working.

IF its the problem, your friend sounds like the best bet. I'd buy the GM pump. IMHO
good luck