What does this sound like?
Ford Taurus, 1995 V6 3.0, automatic, 110K miles.
Car suddenly runs rough one day like it is running on 5 of the 6 cylinders.
The next day as I head off to NAPA to buy its first set of plugs it is running fine. I replace plugs, wires, rotor & cap & PCV valve. The plugs were in remarkably good condition. All were a good shade of brown & the electrodes were intact, though the gap had spread from the required .042 to about .090. Car was still running fine after plug/wire change.
A few days later I head up the expressway on vacation. The first hour or so at 72MPH it is fine, then I notice a little roughness, but it has no trouble maintaining the speed. [Off the expressway I note that the shifting is flakey. On a hill that usually requires a single downshift, it keeps downshifting, then upshifting, and downshifting several times]
It idles rough next morning, but makes a local trip only complaining on that big hill.
2 days later I start it again & it won't make it out of the driveway. I pop the hood & see a rotted out section on the EGR tubing. If I hold my finger over the hole the idle evens out, so I figure I'm in good shape. I buy a muffler bandage-- apply it & get a fairly even idle-- but still no power. [since then I've replaced along with the EGR valve-- but it hasn't helped]
During all of this the check engine light has flashed on for a couple seconds twice. Once while the car was idling & once when under load.
I'm 3 hours from home so I leave it with a strange mechanic. He replaces the fuel filter, replaces an injector, and replaces the MAF sensor.
When I get the car it is still running rough, and has less pickup than it did when it was right-- but it makes the trip home.
I replace the EGR tubing and EGR valve. Still usually runs like it is on 5 cylinders. [Though it still acts like something is coming and going-- one day it will run awful, the next day it isn't so bad. . . then it is again]
Bought a code reader & get the following codes- KOEO
563-- High Speed Electro drive fan circuit fault
565- canister purge solenoid circuit fault
625- electronic pressure control solenoid circuit fault
[the last is interesting because for a couple years this thing has shifted from 1-2 & 2-1 like it had no clutch. [the 2-1 shift will sometimes give you whiplash] My general mechanic & the dealer have both looked at it but had no guesses- just suggest a complete rebuild]
I had 2 codes in the continuous code category;
81-Air diverter solenoid fault, intake air control circuit fault/ air injection diverter
89- AXOD Lock up solenoid (LUS)circuit failure or clutch converter override (CCO) circuit failure.
The continuous codes both began when the EGR was essentially disconnected-- Should I clear them & see if they reappear sometime?
According to the code book, it says to begin with the first code-- Does that sound like a reasonable next step? The HEDF relay is part of the Integrated Relay Control Module.
I just noticed that the HEDF is only for cars with A/C. My A/C was taken out years ago. Should I still be worrying about that circuit or should I go right to the cannister purge solenoid? [or something else?]
Thanks, Jim