Need some help here. Now that winter is here the following is happening:

After sitting in the cold the car will fire up and then immediately die before it has a chance to idle. After I fire it up a second time it runs perfect. It will act fine when it's warm outside or after it's already been fired up once. Seems like this should be an easy fix. Any ideas, and is it something I can handle replacing myself pretty easily?
Thanks in advance.

 

bad iac. mine did the same thing, would fire up then immeadiatly die. if i fired it up and gave it tons of gas then maybe i could get it to idle with my foot on the gas till it warmed up. good luck

 

So you think that it is the Idle Air Control Valve? Is that correct?
The question I have about it being the IAC is this:
From what I have been told about the IAC, if this part were to be bad then I would have to hold down the gas until the car were warm. That is not what is happening to me now though. The car will die after it fires. When I fire it up a second time it will operate just fine, it sits there and idles just fine without any gas applied to it and it drops down the RPM's as it warms up. That is what is leading me to believe it is something else. If I am wrong please let me know, i'll go grab the part asap then. Another thing i've been told it can be is the Cold Start Valve. That a possibility?
Thanks for the help.

 

yeah check those things out first, and if its still busted look for fuel leaks when the car is running. on my truck, it would always suck air into the fuel filter and then when i would start it it would run for a second then die when it hit the bubble.

 

There is no "cold start valve" on an LT1. The PCM uses a richer mixture, based on coolant temperature, to supply the extra fuel when the engine is cold.

I would have responded that you had a problem with the coolant temp sensor, but if it only dies on the first try, and then starts and runs fine on the second cold start try, I would say maybe the fuel system. You may have leaky injectors flooding a couple cylinders, or you may have a fuel system that takes a while to "prime" because the check valve in the fuel pump is not working.

 

Interesting. I recently had my fuel pump replaced last summer. Since then it seems to running very rich. When I step on the gas it smells bad and makes some nice smoke. I've never been sure what I can do to fix this though. I replaced the stock fuel pump with a Walbro 255lph. Not sure if this could have any impact on anything or not. If it is leaky injectors what can I do to fix the problem or find out if it is the leaky injectors?

 

quick way to look for a leaking injector is to hook up a gauge and let teh pressure biuld up. let it sit a while and see if teh pressure bleeds down

 

yeah u can also check when the engine is running to see if you notice any leaks.

 

Put the fuel pressure gauge on there, and check fuel pressure at idle with the vacuum line (35-38psi) and without the vacuum line connected (41-47psi). That will tell you if the fuel pressure regulator is working OK.

Then, as noted in the post above, shut the key off and see how fast the pressure in the system bleeds down. If it starts to drop almost immediately... and keeps dropping, it is probably related to the check valve in the pump. If it leaks down slowly, might be an injector or two. With the system pressurized, but the key "off" (cool engine) pull the rails up and see if any injectors are dripping. You can't find a leaky injector with the engine running.