99 Yukon 5.7 Spit and sputter when cold

[434speedconcepts]

Hey so I just bought this 99 Yukon. When its hot outside or truck is up to temp, runs like a champ. BUT, when its cold or just yesterday, the temp severly dropped after a heavy rain, it fires up, then idles funny then spits and sputters going up the road. I can shut it down and fire it up, it will do it again, restart it a 3rd time and it runs just fine. It had a long block put in it about 40k miles ago. Also, the previous owner put a cold air intake on it (Spectre brand i believe). Any thoughts? I have a brand new MAF in a box and intake air temp sensor new in a box as well. I did notice the I.A.T.S seems to not have the best connection but havent changed it yet. I assume its not a spark issue at all. But, looking for any thoughts on it.

[richard wysong]

instead of throwing parts at it invest in a scan tool that does live data and see what's not functioning properly. I would check the cap and rotor, plugs and wires to start. always start with the basics. it could be a fuel pressure problem as well, change the filter and check the pressure and volume cold. scan tool will tell you if IAT is working

[richard wysong]

ignition coil is also a possibility