Haha well ur all cought up now lol. Any ideas on what could cause that. Im guessing i have either a power or a ground going to the pcm that is not supposed to be a power or a ground or in the wrong spot

 

Ok see where you might have stated that but read it as back probed pin 29 at EEC with O2 sensor unplugged, did not read it as the wire had been removed.

93 engine harness plugged into 89 bronco main harness might be an issue but I have nothing handy to show me the actual pinouts between the two to say one way or the other.

Is that even possible haven't looked yet but 92 to 97 engine harness to main harness uses square connector some 30 odd pins in it, does a 89 use that same connector.

Changes in the wiring/harness, 87-89 then 90-91 then 92 up things changed and move around so it jumps couple times in there 93 in a 89.

That be what I'd look to then, verfiy the PO statements see if was even possible and if so are the pinouts exactly the same and if not had it been repined to correct for any differences.

"the engine is out of a 93 f150 and the 93 engine wiring harness was used and pluged into the stock 89 main harness it was done by the previous owner"

Remote mounted ICM, no longer mounted on the dizzy has been relocated to the fender or?

 

Remote mounted ICM, no longer mounted on the dizzy has been relocated to the fender or? ?? icm ? dizzy?


i was just told it was a 93 engine with 93 harness and that the guy started swapping wires i havent gone through each harness completly but this is the only problem I KNOW OF

 

you need a diagram of the whole oxygen sensor circuit all the way back to the computer. look for any connections along with the sensor or anything near or around it that would either use something close to for volts or anything that looks like it could be tied in to that circuit some how. the computer only thinks the sensor is stuck lean so if it adjusts based to run more or less fuel during the event of a load or introducing fuel and it changes the correct way rich or lean then that should tell you something. if you had power and grounds swapped because of the new wiring then i can tell you a stuck lean o2 would not be your only issue. if the computer is adjusting correctly then you either have different issues or have another o2 sensor. and you said you put the computer in another vehicle and verified that it read correctly so that should also give you a hint.

 

So far I can't find a diagram for the pinouts for both years, not sure what connector number it is.

Found under hood compoinent connector locations diagram for 94 suggesting the conector number is C101 for say 92 thru 96 in line connector however image I found for that connector doesn't look like the one I have laying here from a 95 5.8L for example. See post by Subford #17,

https://www.ford-trucks.com/forums/1...-problems.html

Find nothing for under hood component connector locations for a 89 so nothing to go by far as a number for it to use to get its engine harness connector pinouts. Can't believe no one posted one in all this time but if they did I haven't found it yet, search comes up everything but one for an 89.

 

I was asking if it was still on the dizzy or if it has the 93 style ICM remote mounted on fender.

Give some idea perhaps of what's gone on and at a glance, if over on fender tends verify at least in part OP's statement/claims.

 

i have a simple diagram from a 93 and the pins on the engine computer are different then the pins he said pin 29. he needs to be sure the pin really has anything to do with the oxygen sensor. a great place for diagrams of of the internet is Mitchel diy but that costs money and who know who changed what but the computer pins should still be the same beings he bought a new computer and installed it no problem. on the diagram for the 89 bronco pin 29 goes directly to the sensor on the 93 it should have three wires running from the computer to the sensor. the bronco only showed 2 wires and you have 3 so that should mean you need to be looking at a 93 not an 89. the o2 is not the only circuit back to the pcm. do you have an automatic or a standard transmission.
http://ww2.justanswer.com/uploads/n9...5_015848_D.GIF just a quick search and is hard to read but is what i found.

 

ok so dizzy is the operating system ya must be the original 89 system nothing different looking from my 1990 truck

and it has the automatic aod trans

there is 3 wires to my o2 sensor 1 power wire from ign switch
1 sig wire to pcm
and 1 ground wire

there is also a seperate 02 ground for the pcm on pin 49 i think iv tested it and its good

i dont understand why i would need to look at a 93 diagram other then when checking wire locations

 

because an 89 bronco has a different computer than a 93 and yes wire locations what good does looking at just the 89 diagram do if you have engine controls from a 93. 0n the 93 v8 all of the wires that connect to the oxygen sensor come from the engine computer were as the 89 only 2 do and looks like a ground else were. yes still keep in mind it is an 89 truck but has the different engine control my main point right now is the engine computer seems fine without checking power and grounds some way some how that signal wire as a signal it should not so any affected circuits that have issues of any kind like power feed could cause this.

 

yup i need to veryify that all the engine harness wires have been properly swapped to the correct location . i wonder if there is a way to know for sure what year harness im dealing with on the replacment engine i havent seen any part number stickers anywhere on the harness

and ya i have a complete diagram carguy iv got the huge shop wiring diagram book that i stole from work and i also have shop key 5 account

 

on the 89 the o2 wiring is not part of the engine harness it runs along the rad saddle beside the batter and down that portion of wirring harness is original and i would think if the engine controls on the new 93 block were that different it would set a code for someting other then just the 02

 

If the ICM is on the dizzy then the 93 engine harness was not used when the 93 motor was put in. If transferred the orginal engine harness from the 89 motor over to the 93 motor in the swap than there shouldn't be a problem there far as that goes. That was the correct thing to do and have doubts what would be possible to start with, not a five minute job would take some serious rework to accomplish it.

And yes you are right pin 29 is the correct pin for the O2 sensor, like many circuits that one remains a constant.

 

has the truck always had this issue

 

Yea same with later model its not part of the engine harness either, was thinking more in terms of interference within the EEC itself..

And yea I agree possible it'd trigger other codes if that was the case but at the same time actuators don't throw DTC but are computer controlled.

 

ill go home thisweekend and try to veryfy that all the wires were swapped correctly .


one thing i did do was hook my meter to pin 29 and batt neg and watch the 4 volt s with ign on and eng off i unhooked all the main connectors on the engine harness and the 4 volts remained i then unhooked the 3 remaining connectors that go underneath the body to fuel pump and what not well again the 4 volts remained i then un hooked the big round electrical connector that goes through the firewall and lost the 4 volts finally but i probly interupted the circuit