The Mayan's astronomical observations were outstanding given the tools they had, and investigations of the Dresden codex published by Harvey and Victoria Bricker in 1983 predicted the July 11th, 1991 eclipse according to the Mayan text. Given that the Mayan's didn't have true model of the mechanics and scale of the solar system, could they have done this just with extrapolations from their observations? Lunar eclipse, sure, but I'm not familiar enough with the variables you would need to know in order to predict a solar eclipse 500 years ahead of time to know if it would have actually been possible. The publication says it is so, but in 1983 modern astronomers could predict the 1991 eclipse and it would have been easily accessible knowledge so you wonder if the Brickers could have set out looking so hard for something that they saw it. There are certainly other debates over interpretations of the meanings in the codex so maybe, you know, are they are getting too much credit? But maybe it's totally legitimate interpretation, I can't read Mayan hieroglyphics and interested to know.
Yes, they really predicted the 1991 solar eclipse. I suggest that you read Classic Maya Prediction of Solar Eclipses, by Harvey M. Bricker and Victoria R. Bricker, together with comments and replies (Current Anthropology, Vol. 24, No. 1 (Feb., 1983), pp. 1–23).