Lynch was drafted by the Texas Rangers in the 22nd round of the 1977 Major League Baseball Draft. After three years in their farm system, in which he compiled a 22–27 record and 3.89 earned run average, the Rangers sent him to the New York Mets on September 18, as part of an earlier deal in which the Mets sent Willie Montañez to the Rangers for two players to be named later. The other player the Rangers sent the Mets was first basemanMike Jorgensen. Lynch debuted with the Mets on August 31, against the San Francisco Giants, and gave up four earned runs in just 1.1 inning out of the bullpen. He won his first major league start on September 13 against the Chicago Cubs, snapping a thirteen-game losing streak for his club. For the season, Lynch was 1–1 with a 5.12 ERA in four starts. The Mets and Cubs were perennially the bottom two teams in the National League East for the early part of Lynch's career, however, they'd evolved into division rivals at the top of the N.L. East by the time Lynch took the mound in the second game of a double header on August 7,. The first game was won by the Cubs, 8–6, on the strength of a six run fifth inning, which included a three run home run by Keith Moreland. During a five run fourth inning in the second game, Lynch hit Moreland with a pitch, inciting a bench clearing brawl. The Cubs won the second game, 8–4. In 1985 Lynch went 10–8 with a 3.44 ERA in a career high 191 innings pitched. Baseball writer Bill James said at that time that Lynch had the best control of any National League pitcher other than LaMarr Hoyt. Lynch made only one appearance for the Mets in, pitching 1.2 innings in relief in the third game of the season, when he went on the disabled list with torn cartilage in his left knee. By the time he was ready to return, he'd lost his spot in the starting rotation to the young pitchers on the World Champion squad. The Mets traded him to the Cubs for Dave Liddell and Dave Lenderman. He remained with the Cubs through before retiring.
As an executive
After his career ended, he attended the University of Miami School of Law, and graduated in. Using his law degree and prior baseball experience he was able to land management positions with the San Diego Padres and Cubs, where he eventually became General Manager. Ed currently resides in Phoenix, Arizona. At one point he worked as a scout for the Cubs. From 2010 to 2015, Lynch served as a professional scout in the Toronto Blue Jays organization.