89 Bronco II new to me

[grumpy old man]

Well got my break out box and checking in my genuine 1989 fomoco emissions manual I can find almost no information on the O2 sensor. What it does tell me is that KOEO the O2 sensor ohms should be 1.5 measured is 2.8 and volts should be 0.4 measured is 2.8. KOER hot idle volts are 4.3. Sounds suspicious. The only way I have found to change the O2 sensor is to pull the RF inner fender panel.

As my wife no longer drives I am the designated driver and she has a hair appointment so it will need to wait till I get back.

If someone can use it I have a motorcraft break out box kit 00-00057, 00058, and 00059. I bought it because the 00059 was listed for 90 Bronco, Ranger but when I got it I found that it was for the 4.0 not the 2.9. The 00058 is for the 90 Probe 4EAT turbo and the 00057 is for the 90 festiva, probe MT. If anyone can use it I will part with it cheap.

 

[grumpy old man]

Well got my break out box and checking in my genuine 1989 fomoco emissions manual I can find almost no information on the O2 sensor. What it does tell me is that KOEO the O2 sensor ohms should be 1.5 measured is 2.8 and volts should be 0.4 measured is 2.8. KOER hot idle volts are 4.3. Sounds suspicious. The only way I have found to change the O2 sensor is to pull the RF inner fender panel.

As my wife no longer drives I am the designated driver and she has a hair appointment so it will need to wait till I get back.

If someone can use it I have a motorcraft break out box kit 00-00057, 00058, and 00059. I bought it because the 00059 was listed for 90 Bronco, Ranger but when I got it I found that it was for the 4.0 not the 2.9. The 00058 is for the 90 Probe 4EAT turbo and the 00057 is for the 90 festiva, probe MT. If anyone can use it I will part with it cheap.

 

[grumpy old man]

OK guys, I am back. Had to take a break from the B2, a couple of things rose to the top of the to do list I needed to address. I started to poke around again and put in another new O2 sensor and plugged in the rebuilt Cardone ECM. It now pumps out a fog from the tailpipe which has no smell so I am guessing it is water vapor. The code 14 appears to be gone replaced by a code 41. I pulled the ECM loom out again and found a 22KO 05W resistor in the O2 ground that I cannot find on the wiring diagrams I have, including the Ford EFI diagram in the emissions manual. It does have a 2011 date written on the 60 pin connector and I cannot help but wonder if the loom was replaced with the wrong one. It is a simple matter to eliminate the resistor if it does not belong but I do not want to barbeque any parts if it does belong. As the resistor is not mentioned anywhere in the emissions manual I suspect that it does not belong in there but would like confirmation if possible. Because I am fighting a rich condition It would seem that unwanted resistance in the O2 circuit could be my entire problem.

For whatever it might mean with the code reader connected it will set the code 41 as soon as you do the KOER test.

 

[L\Bronco]

Code 41 makes way more sense, there is no reference to a 14 for a 2.9 that I can find.
Do you have a pict of that resistor?
There should not be anything between the HEGO sensor and ground but wire.
Sounds like you are close
Cheers

 

[grumpy old man]

Code 14 is the PIP circuit which does not make a whole lot of sense considering the problem I have. I have the typical covid brain fog but it did occuur to me to compare what I am reading to what I should be reading. I am reading 4.074 M ohms and 22K ohms converts to 0.022 M ohms. There is a world of difference between 4.074 M ohms and 0.022 M ohms. I can see putting in a 0.022 M ohms resistor to make a slight circuit correction but not 4.074.

It is raining hard off and on here so I don't feel like going out but when I feel like it I plan to check with the local dealer to see if a replacement resistor is available.

Good or bad that much change has to do something. I usually feel pretty good first thing in the morning so probably tomorrow morning.

 

[L\Bronco]

Code 14 is the PIP circuit which does not make a whole lot of sense considering the problem I have. I have the typical covid brain fog but it did occuur to me to compare what I am reading to what I should be reading. I am reading 4.074 M ohms and 22K ohms converts to 0.022 M ohms. There is a world of difference between 4.074 M ohms and 0.022 M ohms. I can see putting in a 0.022 M ohms resistor to make a slight circuit correction but not 4.074.

It is raining hard off and on here so I don't feel like going out but when I feel like it I plan to check with the local dealer to see if a replacement resistor is available.

Good or bad that much change has to do something. I usually feel pretty good first thing in the morning so probably tomorrow morning.

Sorry grumpy, where are your leads connected when you get your 4.074 M\ohms? Are we still on the HEGO ground?
And 14 is a pip circuit code, but it doesn't apply to the 2.9 according to Ford, I'd stay focused on the 41 and the ground.
Cheers

 

[grumpy old man]

I am probing the wires directly on either side of the resistor which is definitely in the HEGO ground wire . The more I think about it the more it makes sense. I am projecting a very possible scenario. The resistor popped way back right after the first smog test throwing it way rich. Which fits with what actually happened. The change from 0.022 to 4.074 ohms completely changed the O2 calibration and screwed up the entire system. Thinking about why it is there in the first place it was built back when California was a separate country. There were 49 state cars and California cars. 0.022 is a very minor adjustment probably put in there to dial the system into Cal Specifications. The ECM is specific to 2.9 4WD California cars.

The code 14 is briefly mentioned in the emissions manual but it doesn't tell you anything about it other than the wire locations and color. I have totally lost count on the number of times I have cancelled a code 14. I would be willing to bet that the code 14 and the resistor are both on 2.9 4WD California cars exclusively. The 10 years I supervised an LAPD repair shop they had a bunch of 85 Crown Vics with the 351 Windsor in them. I was told by a California official that he did not know how they managed to get them into the state and how they were going to dispose of them without shipping them out of state. Point being that the cal vs fed car thing was pretty much chiseled in granite.

I am on my way over to the local Ford dealer to see if they service that resistor. If not I will need to find an electronics store and find an exact replacement. The one I used to frequent for weird stuff like this has long since gone out of business.

More to come.

 

[Tiha]

I miss Radio Shack

 

[grumpy old man]

I miss a lot of stores that used to be. Probably number 1 is the war surplus stores that were around in my youth. way back when you could not get on the internet and have a whatever delivered you had to make it yourself. In many ways I miss the chalenge.

 

[L\Bronco]

I am probing the wires directly on either side of the resistor which is definitely in the HEGO ground wire . The more I think about it the more it makes sense. I am projecting a very possible scenario. The resistor popped way back right after the first smog test throwing it way rich. Which fits with what actually happened. The change from 0.022 to 4.074 ohms completely changed the O2 calibration and screwed up the entire system. Thinking about why it is there in the first place it was built back when California was a separate country. There were 49 state cars and California cars. 0.022 is a very minor adjustment probably put in there to dial the system into Cal Specifications. The ECM is specific to 2.9 4WD California cars.

The code 14 is briefly mentioned in the emissions manual but it doesn't tell you anything about it other than the wire locations and color. I have totally lost count on the number of times I have cancelled a code 14. I would be willing to bet that the code 14 and the resistor are both on 2.9 4WD California cars exclusively. The 10 years I supervised an LAPD repair shop they had a bunch of 85 Crown Vics with the 351 Windsor in them. I was told by a California official that he did not know how they managed to get them into the state and how they were going to dispose of them without shipping them out of state. Point being that the cal vs fed car thing was pretty much chiseled in granite.

I am on my way over to the local Ford dealer to see if they service that resistor. If not I will need to find an electronics store and find an exact replacement. The one I used to frequent for weird stuff like this has long since gone out of business.

More to come.

Just for Sh--s and giggles, try it with a direct ground (bypass the resistor) and see what happens, None of the literature shows it and Ive never heard of or seen one. (I was a drivability specialist at Ford when those were new) I feel it is an add on of some sort. (Are you able to post a pict of it?)
We are getting close!
Cheers

 

[grumpy old man]

I can post the picture that is in my I phone if you can take me step by step through how to post it. I do not get along with electronic devices. What I can state for certain is that it is a factory install. The splice is sealed with a heavy wall glue lined shrink sleeve with the resistor spec printed on it. There is a partial spec, the full spec and another partial spec so it came off a roll. I would bet money that it was an addition needed to pass the full California emissions standard for all new vehicles. I have no doubt that. it would run fine and pass smog with the resistor removed, what I do not know is what effect it would have on the rest of the system. For the sake of a 6c resistor I am putting one back in.

 

[L\Bronco]

I can post the picture that is in my I phone if you can take me step by step through how to post it. I do not get along with electronic devices. What I can state for certain is that it is a factory install. The splice is sealed with a heavy wall glue lined shrink sleeve with the resistor spec printed on it. There is a partial spec, the full spec and another partial spec so it came off a roll. I would bet money that it was an addition needed to pass the full California emissions standard for all new vehicles. I have no doubt that. it would run fine and pass smog with the resistor removed, what I do not know is what effect it would have on the rest of the system. For the sake of a 6c resistor I am putting one back in.

You might be right on the nose with the calibration idea. (They rarely told us what the were doing behind the scenes unless it would help them pay us less for warranty work.)
Be sure to keep us posted.
No worries on the pict. Mostly curiosity.

 

[grumpy old man]

Been thinking about it and what may have happened is that they thought they were home free on the Cal check. Were starting production had all the manuals written and being printed and a glitch came up in the testing procedure so they engineered a slight adjustment to the O2 sensor. They just hid it in the wire loom and did not publish it. Probably sometime during the production year a bulletin was issued but that was the end of it. The chances of the resistor going south before the warranty expired would have been near Zero. The one who would suffer would be some poor schlock trying to figure out the problem without any information, and what do they care 35 years after the fact. It was hidden in the loom and the only reason I found it was that I removed the loom put it on a table started to take it apart and chase all the grounds individually.

Should have the resistor tomorrow, ordered a hundred of them from amazon for $6.00 because they will be delivered tomorrow. The irony of the whole thing is that I have spent months and I don't even want to estimate how much money for the sake of a 6 cent resistor.

If it wasn't for bad luck I would have none at all

 

[L\Bronco]

Been thinking about it and what may have happened is that they thought they were home free on the Cal check. Were starting production had all the manuals written and being printed and a glitch came up in the testing procedure so they engineered a slight adjustment to the O2 sensor. They just hid it in the wire loom and did not publish it. Probably sometime during the production year a bulletin was issued but that was the end of it. The chances of the resistor going south before the warranty expired would have been near Zero. The one who would suffer would be some poor schlock trying to figure out the problem without any information, and what do they care 35 years after the fact. It was hidden in the loom and the only reason I found it was that I removed the loom put it on a table started to take it apart and chase all the grounds individually.

Should have the resistor tomorrow, ordered a hundred of them from amazon for $6.00 because they will be delivered tomorrow. The irony of the whole thing is that I have spent months and I don't even want to estimate how much money for the sake of a 6 cent resistor.

If it wasn't for bad luck I would have none at all

I like your theory, (it has just the right amount of "tinfoil hat" for me!) Good luck schlock!
Cheers

 

[grumpy old man]

Well I don't know what part of the country you were working in but if it was not in the foreign country known as California you missed out on a lot of weird things known only to Cal cars. During those years there were a lot of strange things we encountered that were tweaks to pass the exhaustive initial Cal smog test. At my age memory is a fragile thing so don't remember any of them.
What would not surprise me is that the first run had resistors in all the wire looms and once the Cal gestapo had concluded their random testing the rest did not. I believe strongly in the "tinfoil hat" phenonium.

 

[grumpy old man]

Damn resistors did not come in until about 7pm so got nothing done today. However I was thinking about it all day and I am going to wire a bypass into the circuit so I can see just what it does with/ without the resistor. with the flip of a switch.

I suspect that I am not the only one that would be interested in the answer to that.

 

[Tiha]

I suspect that I am not the only one that would be interested in the answer to that.

We are all quietly waiting to learn something here.

 

[L\Bronco]

Damn resistors did not come in until about 7pm so got nothing done today. However I was thinking about it all day and I am going to wire a bypass into the circuit so I can see just what it does with/ without the resistor. with the flip of a switch.

I suspect that I am not the only one that would be interested in the answer to that.

Awesome, thanks! Can't wait to hear!
Cheers

 

[grumpy old man]

Got everything back together. I am measuring exactly 22.00K ohms across the wire. My O2 voltage has dropped from 4. something to .097 cold and as it was warming up it was steadily dropping, when I shut it off it was down to .067. I do not know if it had gone into closed loop or not but it was dancing around between .065 and .068, so the code 41 should be gone. Flipping the switch did absolutely nothing but it might driving at normal operating temperature. I have no one to drive it right now while I monitor the DVOM and I am totally wiped out, and have no business being behind the wheel right now. If someone comes home in time I will take it out but right now I need to go horizontal.

This covid residue is a total bitch.

 

[wyo58]

Got everything back together. I am measuring exactly 22.00K ohms across the wire. My O2 voltage has dropped from 4. something to .097 cold and as it was warming up it was steadily dropping, when I shut it off it was down to .067. I do not know if it had gone into closed loop or not but it was dancing around between .065 and .068, so the code 41 should be gone. Flipping the switch did absolutely nothing but it might driving at normal operating temperature. I have no one to drive it right now while I monitor the DVOM and I am totally wiped out, and have no business being behind the wheel right now. If someone comes home in time I will take it out but right now I need to go horizontal.

This covid residue is a total bitch.

Very interesting what you have found grumpy, and I'm sure we all will be interested in your final results. But you need some rest big guy get some! It will be there tomorrow or the next day for sure!