PLEASE HELP ME!!!!!!!!


ok, well, i just bought a 1990 gxl, the car has a total of 187k, but the engine was replaced at 115k by the dealer and most miles are highway. Ne-way, before i bought the car, it sat for about 6 months and was driven about 7 times. The same tank of gas was in the car for that period then i bought it. The previous owner told me that after a long ride, it will idle hard and act like its going to stall but i never does. Well, ,my problem is that whjen i start the car its ok. When i press in the clutch and put it in any gear, all of a sudden the idle goes up and down about 400 rpm rapidly, just up and down quickly. The after it hits about 260 degrees, it will idle rough and go up and down slower but more drastically, like from 1000 to 200, every once in a while it will actaully shoot to like 50 and the car will shake a little. This morning, it wouldnt start until i pressed the gas while it was turning over?....bad fuel pump?, clogged fuel filter?? Please help

 

Do a search for TPS(throttle position sensor) adjustment on the forum or on the web, lots of websites are around with this procedure like fc3s.org .
When it starts doing its rough idline thing, check your leading ignition to see if its firing..Max