Strucker is a little bit confusing to me because they seemed to have retconned him into quite a few stories and retconned him in to have relationships with certain characters, but have we ever seen any encounters or fights between him and Cap ? If so, when? I'm sure that they have had some, but I can't think of any stories or issues. The one battle that they had got retconned into being a robot made by Machinesmith. Thanks.
I think it's in Strange tales, the Nick Fury's SHIELD stories. Cap teamed up with Fury fighting a bunch of Hydra agents and caused that black out in New York city in 1968 (I think that was the year).
Other than that, it's in Essential Captain America volume 2, issues 100 to 140. Strucker showed up to kill Cap and then Bucky saved him. Next issue, Bucky turned out to be a robot built by Doc Doom and used by Modok in a secret plan to kill Captain America. Then in the Stern and Byrne books, it's revealed that that Strucker was a robot built by Machinesmith.
Then the Nick Fury agent of SHIELD series in the late 80s that resurrected Strucker and Gruenwald's Grand-evil-master Red Skull (Skull in a clone body of Rogers) funded Strucker's new Hydra plans. Since then, I don't think Cap had any more run ins with Strucker.