Recently bought a manual 5-speed 1999 Passat with 109K+ miles. Two days after having it the check engine stayed on. Was advised that sometimes if the gas cap is not secured that happens. I checked the cap and I also filled the tank with Chervon premium. The next day the light went off and has not stayed on since. The currently problem is that sometimes on a steep hill when the engine goes dead after clutch is released too quickly, the car does not start up immediately. I turn the key there is no sound; the lights blink during start attempts. After about two to five minutes it starts. What are the possibilities?