alright, here goes:
87 BII 2.9 ltr 2wd
sputtering @ appx 40 mph, 4th gear, 2000 rpm (elsewhere too, but not as pronounced) the sputtering quits when i dog the accelerator, to the floor,
also, exhaust smells ultra rich w/ black smoke perodically
KOEO reads system pass, no faults
KOER reads 21 and 42, ECT out of self-test range and HEGO sensor circuit indicates system lean, respectively
i already replaced the dist. cap, rotor, and the ignition coil.
question 1: what is the HEGO?? i replaced the o2 sensor within 6 mos (under pass. floor-pan)
question 2: could the ECT be the cause of all these symptoms?

can anyone (especially mr.shorty) help me?? this thing is driving, or not driving, me crazy!!!!!!!!!!!!!!!!!!!!!!! also, is there a way to test the ECU ("brain") to see if it's bad??? PLEASE HELP 'CUZ I WANNA BLOW THIS THING UP OR SET IT ON FIRE!!!!!!!!URRRRRGGGGGGGHHHHHHHH!!!!!!!!!!!!!
Thanks in advance.........

 

1) HEGO=Heated Exhaust Gas Oxygen sensor (aka O2 sensor).

2) I assume that, when you say, "KOEO reads system pass, no faults" You mean that you got pass codes for both the KOEO and CM (coninuous memory) sets of codes.

3) Double check either the code or your code list. Ken00's list and www.troublecodes.net/Ford show a 42 as O2 sensor indicates rich.

4) A "false" KOER ECT code (and a KOER 41 O2 sensor lean code) are easily set by not having the engine up to operating temperature (and the O2 sensor preheated) when the test is run.

5) A KOER 42, O2 rich code would be consistent with the black smoke and other indications that the engine is indeed running rich. If the O2 sensor code is indeed a 42, then we need to track down why the engine is running rich. ECT is possible, so make sure the test is/was performed on a warm engine.

6) If the ECT code turns out to be a real code, then check the ECT and the associated wiring. The ECT is a basic thermistor, and shouldn't be difficult to test with a wiring diagram and a basic understanding of DC electricity. Also, make sure the engine is reaching full operating temperature (thermostat isn't stuck open or something).

7) for an engine running that rich, also be sure to check the vacuum line to the fuel pressure regulator (FPR) for gasoline and check the fuel pressure.

 

I didn't get a CM set, however, I may want to go back and give it another go.
Other than the two minutes that the manual told me to run the truck prior to the KOER, it had not been run for appx 6 hours or so, so it was a cold engine.
Also, a good friend of mine is telling me that with those symptoms I should check the fuel filter, FPR, and finally the fuel pump, in that order.
I know you mentioned the FPR, but for the filter, I replaced the cannister filter appx 1 year ago and it worked like a charm. However, there wasn't one when I went to replace it last time and the filter wasn't exactly a tight fit, so my questions are as follows:
1) Is there another filter that I am neglecting to replace?
2) If my filter is dirty, how did it get that way? Is it a dirty tank or the fuel lines or what?
Thanks again man!

 

My '87 has 2 "filters":
1) The cannister filter between the tank and the high pressure pump. This may or may not have filter element in it, I don't think it matters either way.

2) An in-line filter between the high pressure pump and the fuel rail.

If they are dirty, yes, it's probably from a dirty tank or dirty fuel lines or dirty gas. I would expect clogged filters to cause the engine to run lean rather than rich, but it's worth doing if the filter(s) haven't been replaced in a while.

 

mr shorty. turns out all it was was my o2 sensor, however, i just pulled the codes again and i'm getting koeo 34 and cm 22 and 41.
last december i replaced the map, o2, egr and something else i can't think of right now. when i initially got the 34 and 41 (last month), i went ahead and replaced the egr valve and the 02 sensor. it runs like a champ now, however, i am still getting the codes! the koer test gave me 11, so we're good to go there.
what's going on? i have already pulled the ground off to reset and i still get the codes. is my ecu (ecm??) bad?
thanks again for all the help.

 

KOEO codes are usually electrical in nature. Check the wiring between the PFE sensor and the EEC-IV computer. Also check the vacuum line between the PFE sensor and the EGR valve.

For the CM codes, I would clear them (I like to pull the jumper wire during KOEO/CM code output rather than disconnect the ground) and see if they keep coming back.

 

thanks man. my truck is at my dad's, so i'll get the chance to check it out tomorrow.