Avengers v.1 #227: Steve's there to offer support when Tony starts doubting himself.
Avengers v.1 #229: When Iron Man's MIA, Steve tries to track him down.
Avengers v.1 #230: Steve worries about Tony's unexplained absence.
Avengers v.1 #233: Steve's so worried about Tony that even Bernie can't snap him out of it.
Avengers v.1 #234: When Steve asks Thor to help Tony, Thor's not sure he can succeed where Steve didn't.
Avengers v.1 #235: Steve worries so much that he's cranky and distracted with the new member of the team.

(I'm beginning to suspect that all of 1983 could go on this list...)

Time for some Ultimates moments!

New Ultimates #2:
* When Cap starts feeling insecure, he wonders if he should be more like Tony.
* Steve and Tony curl up together after being knocked out in separate areas of the battlefield.

New Ultimates #4:
* Tony saves Cap when he gets thrown across a city square...
* And then carries him around so he doesn't get thrown again.
* Cap goes to help Iron Man when he's shot down.

Ultimate Avengers vs. New Ultimates #1: Steve worries about Tony when he's in the hospital.