The radars in the F-14 and F-15 were and are very similar. Both from Hughes (now part of Raytheon, aka RatCO). They could fly the F-14s, but the the big missiles were useless. They used them as a sort of Mini AWACS during the war with Iran and later. It was the presence of an Iranian F-14, in part, that caused the Vincennes'crew to think an Iranian airbus was a warplane on an attack run, and thus to shoot it down.
Here' an article about the F-14 in Iranian service
And here's a page about the Imperial Iranian Air Force. You'll note no F-15s are mentioned (other than Saudi F-15s which shot down Iranian F-4s)