Engine/Transmission (1998.5 - 2002) need some help....

[JBrookshire]

A friend of mine has a 2001 with a auto ctd. He says when he keeps it pluged in it runs fine, but when he drives it to work and it sits un pluged for eight hours it runs bad, he said it misses out and will not run good at all even when it is up to opperating temps... does any body have a good idea what this could be???? it has been in the 20 to low teens in ohio also. Thanks Justin