93 Taurus, 3.0L V6 (not SHO), 75,000 miles
Up until a couple of months ago, I was getting around 26-27 mpg. Then an intermittent problem developed. The car would act like it would lose power or was running out of gas for a brief moment while accelerating. Sometime it would occur only once and other times it will do it several times in a row. Gas mileage dropped to around 17 mpg and would generally run rough while accelerating (especially between 35-45 mph).
I changed the spark plugs, plug wires, distributor cap, rotor and fuel filter. Problem persisted. Checked the air filter and it was filthy (I know, my fault). Replaced air filter and the gas mileage has improved to about 21 mpg, but still having the intermittent power/gas problem. However, this problem seems to be occurring more frequently and more pronounced, especially on cold days.
I took the car to a mechanic to scan the computer, but no codes were registered (the “Check Engine” light never came on). He said to go ahead and replace the throttle position sensor, which I did, but I’m still having problems. I will next clean the mass airflow sensor. He also mentioned that the coolant temperature sensor may be going bad. Before I start throwing lots of money at this problem, do anyone have any recommendations? Replace the O2 sensors? I use a fuel injector cleaner fairly often so I doubt it is a clogged injector, but who knows?
If possible, respond to my email as well
mears@vims.edu