Lincoln/Mercury Repair: hesitation, old fashon, gran marquis


Question
dear steve
I have a 1996 mercury gran marquis 4.3 liter engine with 80,000 miles on the engine.  When I accelerate the car hesitates and shudders, almost feels like it is hunting for the right gear prior to picking up speed and smoothing out. The MAP sensor was replaced about 10,000 miles ago and the symptoms had abated until recently. The spark plugs have about 30,000 miles on them.  Recently my check engine light came on, i had the clerk at auto zone take a readout and he said my right bank
oxygen sensor was weak. i did not repalce the sensor, the check engine light is not on now.

apprecoate any advice you can give me.

thank you   michael85248@msn.com

Answer
sounds like you have an old fashon engine cylinder miss. it can be caused by a bad injector, spark plug, spark wire, or other cause. after 30000 miles you are due for spark plugs anyway so i would start with plugs, wires, filters, set timing (unless yours is distless) start with a tune up. if it still has the problem than send back to me and we will go through other tests.