Possible Fuel Pump Issues in the Cold

[ktmall07]

Hey all,

 

I just noticed the past few days that when I first start the truck up, at idle there is kind of a sputter/choking until I give it any throttle, and a major sputter when I first give it throttle until about 1/2throttle, after which it runs fine.

 

After the truck heats up, the problem seems to go away. 

 

Could this possibly be the fuel pump failing or struggling due to the cold? I should mention, there is no problem starting up, and no other symptoms, just that the engine seems starved in the cold. Any other possible culprits? 

[Pete M]

vacuum leak that goes away once the engine bay warms up? 

[ktmall07]

Do you know of a good write up on where each of the million possible vacuum leaks are located? Haha

[Pete M]

I would start with firing it up cold and while it's struggling I'd wiggle vacuum lines around, especially the MAP sensor line.  then the next time I'd try spraying some throttle body cleaner around.  if it is a vacuum leak, it'll get sucked into the engine and the RPMs will change. 

 

before that though, when is the last time you cleaned the throttle body?  could just be the idle controller is sticking. 

[cruiser54]

Make sure your intake manifold bolts are snug.