wont idle right, some times wont even start???????
 

i have a 2000 gmc rcsb 4.8, flowmasters, shackles. when i crank it cold it takes around 3 to 5 tries to start, it helps to give it gas while cranking it, well thats been going on for a long time, so this weeknd it got worse, it whould bearly start, so i changed my fuel filter, i thought maby it was getting cloged, that didnt help at all. today when i tryed to start it, it would fire for like 3 sec's but wouldnt stay running?? the only thing i can think of is the fuel pump??? yall have any ideas????

Fuel pump or Fuel Pressure Regulator. would be my guess.

catalytic converters could have something to do with it also

how much would a fuel pump, or fuel pressure regulator be?

The Mass Airflow Sensor might also be dirty or going bad.

I haven't looked up a price on a fuel pump for these but before going out and buying one I would see if you can buy or borrow a fuel pressure gauge from the parts store and see if you getting at least 56 psi at the fuel rail.

I had a 2000 with the same issues and yes it was a fuel pump slowly dying that just got worse and worse.....pretty common for that year I learned

My money is bad battery or fuel pump.

if you listen hard you can notice that when it is taking a long time to start you can't hear the fuel pump humming like you normally do right before it starts.

Fuel pump, classic symptoms....

yea the pump makes sum WEIROD nosies some times, or some times i cant hear anything, but my dad said it might be a injector thats beeding off, cause when i start it u can smell gas and it smokes when i start it cold, so its flooding???