Car is running rough. Was only when cold til reached full opp temp, then would be fine. Now when warm it comes and goes mostly runs rough. Cleaned MAS with carb and choke spray, heard may have dammaged by doing this with that spray instead of elect spray. get 4 codes, cylinder 1 missfire, too lean bank 1, (after clearing they come back, other 2 are AIT and MAS these may have been from removing clip and cleaning. There looks to be 2 wires inside mas flow sensor and no other sensor in air flow area from filter to throtle body. 130,000 miles no plug changes, changed fuel filter when problems first arose trying to figure out.
Is my Air Intake Temp (AIT) sen on my 2001 Exp Spt located in my Mass Air Flow sen on 2001 Ford Explorer
by Lostfan in San Jose, CA on November 15, 2009
1 answer 2 comments
ANSWER by backyard tech , November 15, 2009
I believe you are chasing the wrong problem. Although it's amazing that it doesn't run rough with plugs that have 130K on them. This is probably your problem. To know for sure do a smoke test on the intake. Customer Concern: The engine misses or runs rough for the first 4-5 minutes in cold weather. Occasionally it may surge and stall at idle or be hard to start. It runs fine when warm. The MIL may or may not come on and set codes P0171 and/or P0174. Also, it may exhibit a knock or rattling type noise at the Left Front (LF) chain area with or without the drivability symptoms after starting. Tests/Procedures: NOTE: If addressing JUST the rattling noise at the Left Hand (LH) timing chain area, proceed directly to the Program 00M12" for repair instructions. 1. If it is a drivability concern, check the fuel pressure for being correct during the symptom and address as needed. 2. Check the Barometric Pressure (BARO) reading on the scan tool. A typical reading will indicate 155-160 Hz at sea level. 3. If the reading is lower than normal, inspect the air filter element and clean the Mass Airflow (MAF) sensing element. 4. Drain the Powertrain Control Module (PCM) adaptive memory by removal of the negative battery cable for 10 minutes with the key off. 5. Verify that the BARO reading is still high during and after a test drive to verify that the MAF sensor is in good health. 6. Monitor the Short Term Fuel Trim (SFT) reading during cold engine operation, after closed loop is achieved, to verify the engine is running lean. A lean indication is double digit positive values. 7. Nurse the engine alternative fuel, such as propane or acetylene, around the intake gaskets to see if SFT readings can be driven down, pinpointing the area of leakage. Potential Causes: Fuel Pump Leaking Intake O-Rings — Vacuum leak. Mass Air Flow (MAF) Sensor Timing Chain Tensioner — Updated timing chain tensioner and volume reduction plug. Leaking Unmetered Air Tech Tips: This engine typically leaks during cold engine operation only. Once the engine has reached normal operating temperature, the gaskets swell and the leak is gone. Ford issued Customer Satisfaction program 00M12 to address the leaking gasket issue with a service kit that included a timing chain tensioner for the driver side head, due to another concern on some vehicles of a rattling noise issue at start up, and increased warranty coverage for up to 6 years or 72,000 miles. The program has likely expired on this vehicle due to the model year, but the program technical instructions can be accessed for repair information. Diagnostic Codes: Possible trouble codes P0171 and/or P0174 OOM12 is a ford recall that your vehicle mileage is over the recall mileage most likely. I hope this has helped you. If you have further questions you can contact me at AUTOKNOWHOW@gmail.com or 239-313-9334.
COMMENT by Lostfan , November 15, 2009
I wish someone on this plannet knew if my Air intake temp sensor (AIT) was also inside same unit as my MASS air flow sensor unit on my particular vehicle 2001 ford explorer. SOMEONE PLEASE ANSWER THIS QUESTION> I cant test parts I can't find!
COMMENT by backyard tech , November 15, 2009
What are the trouble codes? Is your 4.0 a Overhead valve engine or Overhead cam engine. Need this info before anybody can help you!