I am sincerely hoping that this will solve the issue , and I will be sure to take it on a nice long cruise hopefully again without any intermittent issues , I will be sure not to switch tanks while test driving as well , the first thing I will do is see if the scanner will communicate , if it does that then I will be happy already

Guy

 

Then you need to fix the issue.
I never said that. I said the O2 sensor compensates for other sensors and the engine itself deteriorating. That's why they have an O2 sensor in the first place. If sensors lasted forever and were perfect and engines were indestructible, you wouldn't need one.

O2 sensors just switch slower and slower as the age, until eventually they get stuck lean or rich.
Because at idle there is hardly any air in the manifold. The EGR valve has to barely be open to swamp the entire manifold with nonburnable exhaust gas.

I'd wager a faulty EGR position sensor, or a leaky EGR valve before hand. If it detects the valve is open when it should be closed - it would set a code.
I suppose it could. I honestly don't remember what we were originally arguing about.

And to the OP, as far as re-learn goes. In my experience watching live datalogs, the computer will learn the idle and fuel trim adjustments quite quickly. Within 10 minutes of driving or so.

 

Glad to see you found evidence of a root cause. Let's hope all this leads to a final resolution.

I purposely stood back in this thread to let you work your way to the PCM over the last day or so. I am glad you stuck with the path you were on.

I have seen plenty of carnage caused by leaking caps. and other component failures over the last 27 years of working in the medical electronics industry.

I will keep my fingers crossed!

 

X2.....

 

As soon as they get here I will be ready , I am going to get my iron and solder here on my computer bench tomorrow morning , I am waiting for the shipping date to come live , I usually order stuff on a Thur or Fri for some reason but being Tues I am thinking I will see it by Fri I hope , I will be ready , I am more than anxious to see the end result as well

Guy

 

O.k. here I am Ian a.k.a. Lead Head, hat in hand...............

I OBVIOUSLY misunderstood some (perhaps most, if not all) of what you were saying.
Please accept my apology for that.
I have watched your posts in other threads and do have a great amount of respect for your knowledge and logical approach to answer the questions the masses have asked.

Nuff said ????

Now,
I think we're all trying to get our heads wrapped around this EEC capacitor failure issue rather passionately AND we're butting heads because we're approaching the issue from different perspectives (electronic vs. mechanical)......only to arrive at the same conclusion.

With that said, there should be some things that we all need to realize now based upon this discussion.

The capacitors used in the EEC's we're discussing will fail due to age, voltage extremes, operating environment, or other reasons.
More and more of "our" EEC's that haven't failed, will eventually fail because of the type of the capacitors used in our EEC's.
There are some well known common symptoms of a failed EEC.
A failing EEC (with failing capacitor(s)) can or will cause instability within the EEC circuitry and may manifest it'self as unexplained failures and/or driveability problems within the Ford EFI System.
A visual check of the EEC should now be included in the "Repair Strategy" we use.
A failing EEC MAY NOT display any trouble codes.

Everyone, feel free to add any of your thoughts to the list.
This will be very helpful to all of us and future readers.

Again, my take,

Bob

 

I had a feeling you were watching this play out on the sidelines.

"I have seen plenty of carnage caused by leaking caps. and other component failures over the last 27 years of working in the medical electronics industry."
That explains alot too !!!!

Bob

 

And an update on my truck..........

I installed a new motorcraft TPS and CTS.
Sealed a signifigant TB to upper plenum vacuum leak.
Re-adjusted the idle set screw with IAC and CTS unplugged AND verified TPS voltages within spec.

My stumble problem appears to be cured (at least for now).
I didn't get a chance to test drive it, just in the garage rotating the throttle.

We'll see,

Bob

 

Not to "beat a dead horse" any further, here's a possible explaination of our differing findings and such.

I'm in California, and my truck has a "California" calibrated EEC.
What does that mean ??????
My EEC is programmed/set up differently than the non-Califorina EEC's.
The California Air Resources Board (CARB) had/has VERY strict emission standards and thus the California calibrated EEC.

That could explain alot.

Bob

 

To my knowledge , 02 Sensors are not switches that get stuck lean or rich , a 02 sensor is nothing more than a thermistor or thermometer to simplify the operation , all it does is sense exhaust temperatures therefore telling the computer how rich or lean the motor is running , and yes this is always done after the fact seeing that the adjustment is not fine tuned until the this particular information is received , if in the process of adjustment a control is not responding or goes out of specified range then the code would be generated but again depending on the failure it could not be generated or may be generated after over compensation and or out of range compensation was attempted by the system .
02 sensors fail along the same line as the ECT sensors , they will open and or short , and or the specified resistance per temperature will fall out of range therefore messing up the entire benchmark for the computer
Some may switch though I have not encountered them in my travels , but the switch would still be exhaust temperature related and the end result of failure would remain the same , either open , shorted or out of specified range for the computer to use as designed

Guy

 

Update :

I have gotten the shipping info and to my dismay it will not be here until Monday
Seeing that many ground shipments do not run on weekends anymore unless you pay for overnight/next day , I will not see the Caps until Monday , should have a update on the situation by Monday night

Guy

 

Nope, not even close.

O2 Sensors are chemical fuel cells. They do not have a varying resistance. They generate a voltage in relation to the amount of hydrocarbons in the exhaust. Leaner than 14.7:1 A/F ratio will generate a voltage below 0.450v, richer than 14.7:1 will generate a voltage above 0.450v. Typically you'll see 0.150v to 0.900v.

They will gradually start switching states slower and slower until eventually they get stuck rich or lean.

 

The "switching" refers to the amount of time it takes for the O2 sensor(s) to register lean or rich. The PCM is constantly adjusting back and forth then looking for the signal change from the O2 sensor. As they age or get contaminated the "switch time" becomes longer.

An O2 sensor is a delta-reading device in the respect it is measuring the oxygen content in the exhaust in relation to the ambient oxygen level in the atmosphere. If it is covered in dirt, grease, whatever it will cause the O2 output signal to mis-register accordingly. That is probably the main reason why it is suggested to replace them every xxxxxx amount of miles.

 

Additionally, the "Seafoam in the intake manifold fix" everyone rants and raves about is rather destructive to O2 sensors too !!!

Been there done that one.


Bob

 

It does not truly measure oxygen , if it did it would have to sample the exhaust for this to happen much like the EPA testers used in CA and Northern Va , not unlike any device of this sort , it is measuring by temperature , the computer is programmed with data regarding the exhaust temperature/mixture and what temp regarding that mixture post combustion , this is how it tells the computer what to do and or what to trim , if it was a true 02 sensor then it would actually be sampling the exhaust which it is not doing , the reason the accumulation of deposits affects it is because it isolates the sensor from reading correctly , the actual sensor is encapsulated in a shroud , the vents in shroud get clogged and the sensor itself with accumulate deposits also and the sensor cannot read the exact temp and or it will read changes in a delayed sense , it is not a true 02 sensor or we would be changing them every 10K or less