Nothing.
One of the best cars Chevy ever built.
I would rather drive it than anything Vhevy has come out with since 1990.
The most dependable cars you can buy, without buying foreign.
I have written to Chevrolet GM in favor of them re-marketing the 1986 wagon (or upgrades w/2.0 liter engine) because I have been getting c.25+ mpg. Like the general trend in these "last days" (i.e. - the time of the revealing of the Anti-Christ), discontinuance of the production of the wagon in lieu of monster sized fuel hogs (such as the Avalanche) only serve to hurt the poor, the usual victims in decisions made by non-user friendly executives. The worst of the actual performance of the 1986 wagon is the body rot port and starboard between wheel wells and the usual design difficulties resulting in difficult do-it-yourself repairs.