Problem: went on two different driving trips about 500 a piece... during one of each trip leg about half way through the trip (300 miles out) i look in rear view mirror and for a BRIEF 10 To 15 SEC GRAYISH smoke pours out of the back of the car and then stops and the car is fine after that..

i have checked the oil line and for leaks..NOT IT
during those secs of smoke the rpm does not change or there are no noticable noises from the engine or car it self..

Possibilities: beginging of trip i used 92 gas, half way i used 93 the change in tank might of
> another is Oil coming into combustion chamber but i thought that was black smoke
> biggest one of them all is that the fuel pressure in my car at initial startup is zero. i have to turn the car pump on 3 times to start well and the car runs great. so i think a brief moment the pressure drops and the car misfires..


HElp!!
o another, could it be sparkplugs