while leading, first at the Michigan 500 at Michigan International Speedway (due to gearbox issues) and then at the Molson Indy 300 at Sanair Super Speedway (due to Guerrero crashing). Guerrero finished the season 17th in points with 34 points. Guerrero returned with Team Cotter in 1986 to drive their No. 2 True Value/Emerson Electronics March 86C-Cosworth DFX (numbered 5 at Indianapolis only). Guerrero continued his streak of impressive finishes with a 4th place in the race. Guerrero also scored a pair of 2nd-place finishes, first at the Escort Radar Warning 200 at Mid-Ohio Sports Car Course and the Miami Indy Challenge 200 at Tamiami Park. In the latter Guerrero qualified on pole position and led every lap, except the final lap due to running out of fuel and handing the win to Al Unser Jr. Guerrero finished the season 9th in points with 87 points. In 1987 Cotter sold the team to Vince Granatelli (son of former Indy car owner Andy Granatelli) to form Vince Granatelli Racing with Guerrero driving the No. 4 True Value/STP March 87C-Cosworth DFX. Guerrero scored his first Indy car win at the Checker 200 at Phoenix International Raceway. In the race Guerrero originally qualified 3rd, but the car was declared illegal and Guerrero started 22nd (last) to charge his way up through the field to win. At the Indianapolis 500 Guerrero and Granatelli were one of the few teams to have no issues with March 87C as several teams decided to use year-old 86C models instead. In the race Guerrero qualified 5th and was viewed as among the favorites, along with pole sitter Mario Andretti and defending winner Bobby Rahal. In the race Rahal retired after 57 laps due to ignition problems and Guerrero was in 2nd place to Andretti for much of the race. On the 130th lap a wheel came off of Tony Bettenhausen's car and it hit the nose of Guerrero's car and went flying into the grandstand and where it killed spectator Lyle Kurtenbach. On lap 177 Andretti started to have electrical troubles and Guerrero took the lead. On lap 182 Guerrero came in for his final pit stop and as he exited his pit stall the engine stalled. Third gear had been damaged earlier in the race by the Bettenhausen incident and the car began to get moving, only to stop just outside the pit lane. This caused Al