2000 z24 starting problems

Ive got a 2000 z24 150000kms, 2 weeks ago while at a job site my car didnt want to start.. it was turning over but it woudnt start.

I called my mechanic and he told me its the fuel pump and it would be $700CND to fix.

I didnt have 700 and after doin some quick reading on these forums i decided to try and change the fuel filter.

So i went back out and swapped the filter for a new one and the car started right up, the old filter was so clogged i could barely blow through it.

My car was running fine for the last few weeks with no problems, but i get into it this morning and it will not start again.. its doing the same thing it did 2 weeks ago..

Does anyone think that the new filter could clog again that quickly?

I can hear the fuel pump start up when i turn the key half way.. it runs for 2 secs and stops.

Could the fuel pump be the problem even though i can hear it run?

Any help or suggestions would be greatly appriciated, i really dont wanna spend $700 on a new pump if i dont have to.

Ok i gave the tank a whack with a mallet and managed to get the car started.. took it to the mechanic and he replaced the fuel pump.

Apparantly we have very bad gasoline where i live and this is a common problem in my area.