Chugging At Start Up

[BD7.3PSD]

I have a 99.5 PSD. The motor will surge and have a "chugging" effect upon start up when it has been sitting for an extended period of time. It doesn't smoke at all while doing this. It helps if you speed the engine RPMs up to about 1000RPM for about 2-3 minutes depending on how cold it is and it will come right out of it. Im thinking its either my fuel transfer pump. If anyone has some input on this, your help would be greatly appriciated.
Thank You!

[scraph]

How cold are we talking? Chugging is not abnormal during initial warm-up of a cold engine ... if we are talking about cold climates.

[BD7.3PSD]

I think its been around 50 degrees in the mornings here and it gets up to 70's nd 80's during the day. My Dad's 99 PSD dosent do this at the same temp, so idk.