Hesatating to start

[5.3LSilverado01]

I filled up with some crappy gas a little while back, and then one morning I started my truck, it had to crank over for a second or 2 before it started. And while starting took a while to climb to idle speed. The dealer said change the fuel filter, $50 and new filter later, same problem, only worse!!! This only happens sometimes, and only when the engine is cold. Every other time I start, 1/2 a crank and it fires right up, almost instantly. Its not the fuel filter, what do you think it is? I've ran a few bottles of cleaner through it, fixes problem temporarily. The dealership said if it doesn't stop when you change the fuel filter, we'll try pulling and cleaning the injectors, at my cost!!! Before I go and pay more money, anyone have any ideas? Any parts the warranty can change before I pay to clean the injectors?

Thanks,

Chris.

[95 Silverado]

When it starts does it idle up as it should when it's cold? If the coolant temperature sensor is out of range it may not be richening the mixture for cold starting (like a faulty choke), does this only occur when the engine is cold? I don't think cleaning the injectors would solve this.

[5.3LSilverado01]

If I crank it for a second or 2, and it starts, it slowly makes its way to 500 rpm, If I crank it for a second or 2 and it doesn't start, i'll stop, the crank again, this time it will frie right up (normally starts). Yes, olny when its cold. But then sometimes when its cold, it will start normally. Probably 6 times out of 10, it wil start normal when cold.