1998 GMC Safari engine miss fires when cold

I've checked everything except fuel pressure, I can hear the fuel pump but just now 10.27.2008 @9:30 pm I crancked again and it started up it took a few cranckings to start but it did it idles real smooth with no missfire but when I accelarate it starts to miss fire and puting when I let go of the gas pedal its fine. Again it does it real bad when its cold, when warm very little miss fire barely can feel it. Thanks I appreciate all the help that I can get.

I've checked everthing except fuel pressure I do hear the fuel pump come on i've done a tune up not that long ago. I went and cranked it again and it started, when cold and idling it runs smooth no missfire when I accelarate it starts to sputer and missfire. This problem got progressivly worse thanks for the help

Ok i'll check the fuel pressure tommorrow but can you tell me what the pressure should be at, thank you

Hi i've checked the pressure with a fuel guage, when I turn the key to on without turning engine on for 2 seconds it reads 64psi then it immediately drops to 54psi (64psi while the pump is priming for the 2 seconds). I tried getting the van started this morning but this time no luck, I think maybe the fuel pressure regultar could be the problem? It use to start up right away when I first got it soon after it would always take same cranking before it would start up also I forgot to mention when fuel was low in the tank almost to empty it would bog down on me like it did not have fuel I would have to press on the pedal very lightly to pick up speed. Again thank you very much for your help please let me know as soon as possible.

Hi just finish putting in the pressure regulator and yes the same thing it won't crank over, I can smell the gas from cranking so much I don't know if it's getting to much gas or what, one thing I noticed is when I stop cranking the motor it attempts to crank over it gives me a few bucks then it stops. How do I check for a leaking injector please let me know. Thank You