i have a 88 pioneer that runs rough, it ran ok when i drove it home, but after doing some maintenance it is running rough. i cleaned the throttle body, replaced plugs and cap and rotor and swapped out the O2 sensor with one out the parts jeep i got in the trade i made. symptoms are surging idle, black smoke and poor fuel economy. my estimate for the economy is around 9-10 miles per gallon. i am not certain due to the larger tires. i also replaced my muffler with a cherry bomb last night because the seals had blown out on the other. i also replaced the ccv and pvc with the ones off of the parts jeep. if you need anymore information i will try to help as best i can but i have only had the jeep for 2 weeks so i am still learning about it.