Ok, like the title says, trouble starting after my 99 blazer with the 4.3sits for a while. It just started doing this, and it starts every single time, but after I give it some gas while cranking. Now, I know most of you will say check fuel pressure and all the fuel stuff, because the pump was never changed as far as I know. But I was having timing problems because I removed the distributor and it was starting in am instant before I adjusted timing. So now my timing is as close as I can get it without a scan tool. Now it runs like brand new, just having trouble starting. My battery is a bit weak, and I'm getting a new code. For air injection. I don't remember the exact code though. Could that have something to do with it? Sorry for the long post, just trying to eexplain the best I can. There may be some mistakes due to me being on my phone and it won't let me scroll through to see what I'm typing. So sorry! Thanks I'm advance to all who help!

 

Simple test, turn ignition on(not started) and listen for a gentle hum from gas tank on the driverside just before your rear tire. Stomping gas has little to do with it starting. Your fuel pump is designed to automatically generate atleast 65 psi on ignition and usually near 90 psi running. If no hum or you find the pressure is low after checking the def fuel pump or filter.


If the battery then you can easily have that checked or replaced and can very well be the issue but my money is pump...



I would suggest pumping ignition 3 times for about five seconds each before starting, if it starts right up then you have your answer and its likely a sign that repair is coming hope this helps

 

Although what you said can also happen and be the case, 99.99999% of the hard starting when cold issues i have ever seen with a 4.3 vortec have been due to bad spider injectors.

Go rent a fuel pressure test kit from your local auto parts store and test the pressure. it should be 60+ psi with the key in the run position and the engine OFF and it should not drop below 55 psi for 10 minutes after being primed. If the pressure drops below 55 psi in 10 minutes (which i almost guarantee it will) then you have a leak somewhere. like i said more often than not its in the spider injectors, but to make sure take the plastic air intake boot off your throttle body then open your butterfly valve and look inside the intake with a flashlight and if you see any gold clean areas (anything besides black basically) then you found your problem. If you dont see any washed looking areas chances are its still the spider but its leaking in the back where you cant see but it could also be the pressure check valve in the fuel pump which is far more rare of a problem than the spider.

just my .02$.. you notice a lot of common trends being on here for so long hope this helps

Edit: Sorry i didnt read youre whole post before i replied. Still do what i said and report back but i now have a feeling that you are having other issues.

 

I will test the fuel pressure, but I doubt it's that. Before I adjusted the distributor it started perfectly. My throttle blade and all that is very clean because I cleaned it during the LIM gasket change. I really hope it's not the pump, but with 106,xxx miles, it will probably go soonn.