My 1999 GMC Yukon SLT with 103,598 miles wouldn't start. I had replaced the plugs, wires, distributor cap, and rotor about 1500 miles ago with new taylor 9mm wires, Bosch 2+ plugs, and Accell rotor and distributor. Last monday when my wife (of course my truck knows better than to stop running for me) went to start it it wouldn't start. There had been no previous indication. So i towed it home and began the diagnostics. Fuel...Check, Spark...Check, Fuel filter, Pressure...Check. OBD-II Scan...Check. The only indication of a problem was fouled out spark plugs, but I firgured that was because I had cranked it a number of times trying to find the problem. Well a week later and a $180 dealer fee later the truck is running as perfect as before. It was the distributor cap. It was shorting out and sparking 3 plugs at a time. I think it is important to note also that the amount paid was $95-diagnostic and $80-Parts. I had to buy the parts and put them on myself. Otherwise it would have been $425 for them to put a new distributor on for me... Hope this helps anyone needing to change distributor and rotor. The dealer did comment that the wires were very nice and I was able to get a refund from Summit Racing for the Distributor and the Rotor.