Forgive me if this has been answered, but I didn't see anything that was really the same. I have a 98 gmc jimmy slt. Fuel gauge stopped a couple years back, so I put a fuel pump and filter in it. Recently it has gotten harder to start. It cranks over maybe 7 or 8 times, starts, runs for 7-10 seconds then dies. Crank it the 2nd time and it fires right up. Does this just about every time I get in it. Then one day the fuel pump just crapped out. I figured that was my starting problem. Replaced the fuel pump and filter. The fuel pump does work now, but the starting is the same. It also idles down to about 500 rpm at times and idles rough. My truck is very nice and loaded, but is starting to sound like an old piece of farm equipment. Thanks in advance for the help.

 

So, you want to let us in on what brand the fuel pump was before this one.. and where you got it?

You need find a Fuel pressure gauge, check pressure key on engine off, then watch and note how fast the pressure leaks down.

 

I know the old pump was from oreilly. Looks like the problem is the fuel pressure regulator. It is leaking fuel into the manifold, making the truck act like it's flooding. Another symptom is poor fuel economy, even more poor than normal. New one was about 45 bucks.

 

Reading your OP I thought of the fuel filter but that would be more of a consistent issue. Unless when you turn the key & the fuel pump primes the system without it being drawn off it has enough fuel for it to start & run for a bit. But it can't sustain the pressure & hence the engine dies.

Then I read your last post & yeah if the regulator is leaking then it's not getting the right pressure to keep the engine running because of the leak. It'll fire up & run & then literally runs out of gas.
With a fuel pressure gauge hooked up you should be able to turn the key to run & have it hold a pressure of 55 for 10 mins I think.
Use the search feature & look it up in here.

 

I would not start guessing like you did with the fuel pump (guessing can get expensive)

Unless your old one died but from the sounds of it you replaced it blindly
Id run this diagnosis

96+ Fuel System Diagnosis - Blazer Forum - Chevy Blazer Forums

post back with your finds someone or i will surely help you

 

Thanks for the advice guys. Not replacing anything blindly, fuel pumps don't exactly come cheap as we all know. Mine completely died, had power to the unit, but it would not come on when the key was turned on. The new one does come on when the key is turned on. I always replace the fuel filter when a fuel pump is replaced also.