bum running ranger

[The_Eric]

Boy, IDK... with such a wide range of codes going on it could be a few things.

A possibility - do you think maybe someone disconnected the harness and turned the key on? That would set and store oodles of codes. Or are they persistent? Do they keep coming back? If that's the case, I'd say look at the wiring harness really well. Look for chaffing, bare or broken wires. Also verify the power and ground connections (especially the grounds - all of them). After that, maybe a bad ECM?

 

[eljefino]

I'll repost my code sequence in 3 digit format... makes more sense. Remember it was about having a stroke gobbling random extra fuel. This code pile came before I started messing with sensors and whatnot.

172: (R,M) Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control

173: (R,M) Oxygen sensor not switching - system is or was rich - Single, Right or Rear HO2S - Fuel control

176: (M) Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control

177: (M) Oxygen sensor not switching - system was rich Left or Front HO2S - Fuel control

then repeat again

my original crayon crib sheet reads

5125221172173176177172173176177

You could say I have a 125: (M) TP voltage was lower than expected - Fuel control and a transcription error with the 221.

From an ergonomics of repair perspective, it's nice to know before transcribing if one has 2 or 3 digit codes; the pauses are not that clear cut, IMO. Makes me want to shoot a youtube of the blinking light so I can submit for additional beratement.

 

[punisher]

Clear all of your codes. You will have to get a proper baseline/starting point to find out where you are. After clearing codes, take it on a drive for a few miles, make sure it is warmed up properly, then pull codes again. Sometimes you get hit with so many codes you end up in a W-T-F situation.

I have had situations like that in the shop where you have 7-8 codes, and they were caused by a single fault, but if you got out the "H Manual"(Ford big book of emissions/performance diagnosis) and tried to chase down each code by itself you would be there for hours/days.

 

[mechtech2]

Right. O2 codes don't mean the O2 sensor[]s are necessarily bad.

Like I said, the FPS is #1 to check out. You'll fix it or eliminate it from the equation.

 

[MC5W20]

Originally Posted By: eljefino


Truck idles okay (but sometimes you can pick up a miss) and goes WOT okay but is juddery at mid-throttle, cold or warm, damp or dry. Is a stick shift so you feel it.




If all other testing doesn't reveal the problem. I have found that the juddery mid-throttle is usually the fuel injectors. If it is a beater truck and you don't want to put any money into it then you may have to live with it. The fuel injectors can be cleaned on an ASNU machine.

 

[punisher]

Something to bear in mind with a 4.0 OHC is that they idle rough. It was a known concern and Ford released a service bulletin for the problem. It stated, essentially, that the engines idle rough due to camshaft characteristics, and that the roughness should be regarded as normal operation.

We made a few dozen copies and stapled them to ROs to give to customers.

A good thing to remember when troubleshooting lean/rich codes on a FoMoCo vehicle is that a bad MAF reads rich at idle, and lean during accel/engine loads. This is why you sometimes have both lean and rich codes with a MAF concern, and having a scanner with a DCL is about the only way to diag it without throwing parts at it.

 

[eljefino]

For the record it was the o2 sensors getting lazy and switching slowly. Probably poisoned by the FPR getting raw gas into the intake.

Really felt like a bad spark plug wire lugging at 600 rpm at speed, power on off on off, almost like a 1 cyl "thumper".

This masterful diagnosis came with cooler weather and 45 sec of decently blissful driving before it went in closed loop. Also, remember, WOT ran good.

Could never get at the wiring disconnect so I cut the black signal wires. Ahhhhh.