Expert: Dennis W - 9/13/2007

Question
Hello,
I wondered if you could give me some pointers because I haven't been able to find any answers. I have a 96 Ford taurus 3.0L OHV. It has been running ok normally, but at times the temp runs hot and fluctuates along with it not wanting to accelerate as it should. If I try to accelerate hard, it will act like it is smothering itself and not want to raise speed. Almost like it is breaking up ignition wise. Yet, if I ease off the gas and depress the pedal slowly, it will speed up eventually. It doesn't seem to do this all the time, just frequently. The accelerator problem will happen up hills and on any mashing of the gas. The heat fluctuation happens in traffic or uphill also. I have scanned it numerous times and not getting any codes. So, how can I fix this thing w/o a code to tell me what to fix?
Thanks for your help.

Answer
How is the engine tune as far as plugs, wires, filters? If any of these need maintenance then get 'er done.

For the problem you describe, I suggest disconnecting the MAF sensor, which is in the ducting between air filter and engine. If the symptoms go away with this sensor disconnected, replace it. You may notice a difference in how the engine runs, but driving it should tell you if this is causing the original problem. With the MAF disconnected the PCM goes into a failsafe mode, it is perfectly safe to drive it this way temporarily to see if the problem goes away. (this will also turn the check engine light on and set a code)Your description of the symptom sounds like a classic MAF, and they rarely set codes. This engine also had problems with CAM sensor, but these will almost always set a code P0340.

For the overheating, thermostat is a good place to start, it may be sticking and not opening properly sometimes. Also check to make sure the cooling fan is working. Running too hot under load or in traffic is usually an indication of low flow, either air or coolant.