Hello. I have a 86 Deville with the almighty 4.1, the clock says 211k, not sure if its original. Anyways Ive had this car for 3 years and it always ran great, then all of a sudden lately going up a steep hill or a long grade it loses power and starts bucking and cutting out. Changed the fuel filter and still no difference. Its seeming to get worse. Driving in town it runs great. Any ideas? Im thinking it could be a weak fuel pump, need some ideas. Also, is it normal for the 4100 to smoke a little bit and use some oil? Thanks

 

Man at 211000 I think a little smoke wouldn't be out of character at all. Don't push it too hard with that kind of mileage. In regards to the miss, have you had a look at the distributor cap. Check to make sure it doesn't have a crack in it.

 

I dont think its an ignition problem. When youre climbing a hill and you get toward the top its like it runs out of fuel or cant get enough fuel. I just changed the filter last week. As I said in town it doesnt miss a beat, its just when its under a hard load. Any ideas will help! Yeah this car only smokes after its been idling and then take off. It doesnt foul plugs or burn alot of oil.

 

OK now I hear you, then maybe go for a fuel pressure test. The pump could be weak and not up to pressure. When I changed my pump I went for a turbo-pump, which was better than OEM. I had vapour lock in hot weather and now the problem is gone. Not that bad of a job to change after you drop the tank.Do you have one filter on that car or two?? Carb. or DFI??