Here's a couple threads that show plugs from engines that don't run a tuner (at least at the time they didn't).


https://www.f150online.com/forums/sh...ht=spark+plugs
https://www.f150online.com/forums/sh...ht=spark+plugs

 

Thnaks for the link T-bird. I guess the ceramic does look cleaner on the other people's plugs.

If I were to have a fuel problem as suggested, how would I diagnose that? There is a dyno shop down the road, I can check with them and see if they can give me the current a/f ratio and then run with the edge and see what it come out to?

 

I would install wide band O2 sensors. They read a broader spectrum then the stockers and will allow the PCM and the tuner to work better together.

 

Would that be for all 4 of the O2 sensors or just certain ones?

 

Hi.

Sorry, but that's dead wrong and can't possibly work.

The factory narrrow-band sensors are only used as 'switches' around a very narrow range w.r.t. Stioic ( 14.64:1), hence the name 'narrow-band'.

The PCM is only expecting these voltages and 'thresholds' the values ( translating it into "rich/lean") to keep the A/F's at Stioic when in closed loop operation ( part throttle, most of the time).

The PCM does not care about, recognize, nor can it possibly use the output from a wideband sensor !

In fact, the truck would probably not run correctly since the specs for the two different types would be different.

On a vehicle with four sensors, it's only the front two that are involved with A/F measurement for the PCM.


Cheers
Bubba

 

Interesting discussion, but now im nervous w/ my edge..

 

Spark plugs don't lie either. I would check them (or at least the #1 plug).

 

I think my excal provides abetter burn, but who knows with the amount of mileage i drive it may keep the carbon burned off....remember the little old lady that drove only to church ? thats probably why he car never ran very well....all carboned up RUN IT HARD AND BLOW THAT ***** OUT !!!!!!\

 

Interesting....but your forgetting one important thing. PCM's used on modern vehicles are adaptive, they learn. The only reason it reads within a specific range is because that's all the information it's given. This is why if you drive like a granny 95% of the time and then you stomp the throttle the engine lugs before it starts to move. When you install a tuner, the PCM adjusts fuel and timing based on the information from the tune. The richer A/F ratio is the result because the O2 sensors are still giving the stock narrow band of readings.

 

Hi.

First, it's apparent you do not understand the two modes of fuel /air control.

Closed Loop: A/F's determined by rich/lean switching info from the front O2's to keep the vehicle at 14.64:1. It will STAY at the ratio ( or very close to it - it will drift around some, as the O2's switch like crazy and the PCM tries to compensate overshoot/undershoot), until it goes open loop, based upon things like engine load and other factors.

Open Loop: A/F's are derived from pre-programmed fuel tables in the PCM (the 'map', if you will), again, dependent upon several factors (temp, load, MAF counts & a bunch of others). The O2's are no longer involved at this point, which highlights why you are wrong.

Yes, a tuner does change fueling, but only in Open Loop, where the O2's signals don't count.

I've got the data to support this - as I type this, I'm looking at my datalogs from a 92 Octane performance tune, & as long as the PCM is in Closed Loop, the A/F's I measured are around Stioic ( ~14.4 - 14.7) all the time, from idle up to approx 2500 rpm or so, at which point the load requirements dictate going to Open Loop. Once it hits Open loop, the A/f's start to go richer, as they should, as the fuel tables dictate based upon all the various inputs, except the O2's.

So, you're missing the point. The PCM cannot and does not use the full-scale analog output from a wideband sensor. It's simply not programmed for it. Period. That's why a narrow-band sensor is utilized - besides being cheaper, it is only accurate around Stioic, as all the PCM requires & is expecting is a very limited change in voltage, so that it can detect rich or lean. That's it.

This has nothing to do with adaptive strategy for fuel trims - completely different beast.

The key thing to remember, in the Ford PCM software implementation for fuel injection control, only binary (rich/lean) feedback is used to tell the PCM where the ratio is W.R.T Stoic at any given time in closed loop. The core logic cannot interpret a linear voltage output from a true wideband sensor. In open loop, different story - the A/F's are not controlled by the O2's.

You must use the specific, pre-calibrated narrow-band O2 sensor specified for your specific MY truck. Anything else, and you risk some damage, as the PCM depends on accurate O2 calibration to know where Stoioc is in the first place.


NOW - having said all of that.... IF an aftermaket tuner attempts to add fuel during closed loop operation for some reason, or an end-user decides to 'richen' it via a manual adjustment, and goes too far, it's possible that you risk running into the control limit for the PCM in an extreme case, and Stioic can no longer be maintained. That's one reason a proper custom tuner like Mike Troyer, limits the amount of adjustment permitted by an end-user in his custom tunes - for safety, and "bonehead-proofing". Casual adjustments, just 'cause you can, are just plain dumb without the measurement data to justify 1) why?, and 2) what did it actually do?

For more, go to Motorcraft's site - there's some good OBD-II tech articles. I'm sure you mean well, but your advice just does not make any sense.

But hey, I'm just a dummy (thanks Duke!), so... you gurus out there - [Quintin, Blue, Anthony], step in here & either back me up or correct me, whatever the case may be

For Rochester - sorry man - can you say 'thread-hijacking?

Happy Thanksgiving, folks!

Cheers
bubba

 

most of the rest of your post is pretty accurate, but this is just nonsense

 

Do yourself the favor and remove them now, clean them up, and use the nickle anti-seize on the extension part of the plug. They recommend you NOT use anti-seize on the threads. Doing this should help prevent future problems with breakage. I WAS one of the broken plug victims. Factory dealership broke 3 of them and tried to make me pay for the entire repair. I bitched, moaned, lawyered up, contacted local news, and filed complaints with the attorney general, before they paid all but the $150 I was quoted for the Tune-Up. And yes, $300 was real expensive for the other guys Tune-Up.

 

Its really pathetic that in this day and age, something as trivial as a spark plug change can be botched so badly by Ford.

I mean it is not rocket science, we dont see other manufacturers having this issue.

 

Whats nonsense about it? It is called "cylinder wash".. and obviously you know nothing about it.

 

I know that cylinder wash can be a problem if one is really putting the fuel to the cylinders, but can a tuner that offers only 5-10% gains really be causing a problem? Maybe I am missing something here, or I just don't realize how much more fuel is being added. Anyway, I can see maybe extended rich runs may be causing his plugs to look the way they do, but to be enough fuel to wash the rings? If changing the fuel about 5% can cause this, then I need to re-think this tuner business. Thanks.