I have a 1986 Isuzu I Mark with an L4 1471cc L.5 engine with manual transmission.

My problem is it sometimes it starts jerking and jumping when I am driving down the road.I can push in on the clutch and give it gas and seems to run all right until I engage the transmission. Other times I get it going until Iget it in third gear and it starts acting up again. Can anyone please help me with this problem? The car gets good gas mileage and with the price of gas I need this car to run .

Thanks