2000 Taurus SEL 24V - rough idle, blinking check engine light
Hopefully I've posted this in the correct area., this is the first time I have used any forum to repair a vehicle.
I have a 2000 Taurus SEL 3.0 Duratec 24V. 94,XXX .miles. It has a rough idle, check engine light, occasionally the check engine light will blink (while blinking it seems as though there is no kick down acceleration and if I put my foot down on the pedal it accelerates slowly). This is ONLY a problem at idle except for slow acceleration when the check engine blinks. The idle does become more rough when the A/C is on. Rough idle is not affected by clearing the codes out of the ECM. I have only pulled codes once as I do not have a code scanner. I cannot remember the specific code other than BANK #1 Lean.
I have read multiple posts about a rough idle on a duratec, a vacuum leak is usually blamed I do not believe I have that problem. The last owner had a mechanic say it was potentially a "burned valve" but he also never looked at the vehicle or had near as many details as I have. This cannot be that difficult or expensive to repair since it's only an at idle problem.
I replaced the fuel filter, spark plugs, the old plugs did not appear to be worn, fouled, or defective. replaced the upper intake gaskets, ran Amsoil PCI fuel cleaner additive, and replaced the PCV. I noticed that the intake had a light buildup of engine oil. My guess is oil buildup has been corrected by replacing the PCVs. I cleaned the throttle body with approved cleaner and a toothbrush, along with spraying clean the IAC valve, EGR valve, and MAF sensor all with the appropriate cleaners. Inspected the Coil Over Plug coils and boots and there appears to be no cracks or carbon traces of a misfire.
It also does not appear to have any issues with the cat converters although the muffler does seem louder than normal (I'd guess due to the rough idle)
This all leads me to believe I have a sensor issue. If I remember correctly the O2 sensor readings are not taken into account for the first few minutes of operation until the vehicle has warmed up and I have had the blinking light with poor acceleration happen within 30 seconds of startup. I'm out of options on repairing this issue since I do not have a scanner and I cannot afford to replace various sensors until I find the right one.
System too lean would tell me either too much air, or not enough fuel so I do not believe that this is an ignition problem. I have ruled out a vacuum leak after inspection of all hoses and using throttle body cleaner sprayed over the manifold and hoses.
The previous owner of the car sold me the car with the rough idle condition, he also gave it a tune up and tried to diagnose the problem but he did not look deeper into the problem His 18yr old daughter did not feel comfortable with it's rough idle....apparently a fully loaded SEL model, leather seats, mach stereo, moonroof, heated rearview mirrors and polished rims, and immaculate condition. Some kids are just too spoiled. She wanted a grand prix, I'd pick a newer ford over a pontiac any day I'm very proud of Fords quality improvements over the years and disappointed in chrysler and GM products.
I'm sure there's more information I can add to my diagnosis of this car but LOL, if no one replies to my post I'm just talking to myself.
Please help me with this issue as it is causing me to lose sleep thinking about it as I'm sure many mechanics do.