Another factor was the lack of support for the Ottoman fleet, which was largely composed of galleys at the time. For a substantial commitment, the Ottomans would be facing a challenge similar to that of the Spanish armada: namely, running a gauntlet of hostile nations. They'd be on their own after leaving Albania/Greece, and could face a challenge from the Venetian, French, or Mamluk fleets, all of which would have advantages of having nearby ports and supplies.

Grenada was too far away for the Ottomans to safely gamble an army and a navy of a size adequate to turn the tide.

Source: Lord Kinross, The Ottoman Centuries

The inner divisions and struggles of the Muslim states played a big role. The Wattassid dynasty of Morocco were struggling to establish their rule, and the Hafsids of modern Tunisia were losing influence to Bedouins and newly-independent cities. At the same time, Castile and Portugal established military bases at the North-African coast, and the Ottomans would only extend their domain in the Mediterranean in the coming decades. Andalusian Muslims had already contacted the Ottoman Sultan Bayazid II. in 1487 pleading for help, which led to an Ottoman fleet sent to survey the Spanish coast. However, later pleas were unsuccessful, surely also in connection with Spain's preeminence in this region which would determine the Spanish Muslims' fate until 1611. Similar later Granadan missions to the Egyptian Mamluks only achieved Mamluk diplomatic pressure exerted on the Spanish kings (e.g. around 1501), again because of the distance between Egypt and Spain.

Sources: Harvey, Leon Patrick, Islamic Spain: 1250 to 1500, Chicago 1990. Del Marmol Carvajal, Luis, Historia del rebelion y castigo de los Moriscos del reino de Granada, Tomo I, Madrid 1797.

No Muslim leaders at the time had the capabilities to launch a full-scale ground invasion of Iberia. However the Ottomans did send raiders to attack the Christian controlled portion of the Spanish coast in 1487, and even more interestingly sent a fleet in 1492 to rescue Jewish and Muslim refugees. I've never heard of Maghrebi kingdoms explicitly helping the Andalusians like this, but they might have and they were certainly raiding coastal Christian communities.

This strategy of hit-and-run naval raiding, as opposed to land grabbing invasions, was the main strategy used by the Ottomans and Maghrebiyn against Western European powers at this time, and continued at some level until at least the 18th century. Compared to full ground invasions pirate raids require less commitment and risk. Also the slaving and looting that was an integral part of these raids devastated Christian society in some coastal regions and made Muslim leaders and sailors filthy rich.

Source: Donald Edgar Pitcher, An Historical Geography of the Ottoman Empire

As far as I'm aware, there wasn't a similar call to arms from a Caliphate as there was from the Pope. A Caliphate, who would have been a pretender to the rest of Islam, in Al-Andalus didn't even exist by 1031. In the end, even with Cordoba, Al-Andalus was a backwater on the fringe of the Islamic world and the pragmatically unimportant or beyond the reach of the real Islamic powers. An equally fair question is why did the Crusaders sack Constantinople during the Fourth Crusade?