I have a 1987 Jeep Cherokee Laredo 2 door with the 4.0L 6cyl, 4wd, with the 5 speed tranny.

I was running great and then I started it the next day and it runs really rough. When I'm at a stop (in gear or not), it vibrates a bit, but while accelerating it is really bad. I can feel the vibrating especially through the shifter which shakes like crazy.

Funny thing is that when I am slowing down in gear (allowing the engine to brake) there is no vibrations at all, but as soon as I press the clutch or gas the vibrations return.

I checked the manifold pressure sensor, and it was good. I replaced the spark plugs, wires, cap and rotor, but no difference even though they looked pretty bad.

Car is not equipped with OBD so no check engine light.

I need to drive 600 miles on Friday and I really need to get this working good.